THE  NEW  AIR  WORLD 


FIG.  4.  —  INSTRUMENT  SHELTER.     Frontispiece. 
(Page  66) 


THE  CxuKX 
NEW  AIR  WORLD 

The  Science  of  Meteorology 
Simplified 


BY 


WILLIS  LUTHER  MOORE,  Sc.D.,  LL.D. 

PROFESSOR   METEOROLOGY   GEORGE    WASHINGTON 

UNIVERSITY,    EIGHTEEN    YEARS    CHIEF 

UNITED   STATES  WEATHER  BUREAU 


BOSTON 
LITTLE,  BROWN,  AND  COMPANY 

1922 


IYIU 

>  i  >  >  •?*  -1   »**.«•  •  !•••'•, 

>  '  »->  j    i  >   •     '       • 


Copyright,  19S2, 
BY  LITTLB,  BEOWN,  AND  COMPANY. 

^122  rights  reserved 
Published  October,  1922 


PBIKTED  IK  THE  UNITID  STATKS  OF  AMEBICA. 


AFFECTIONATELY  DEDICATED 

TO 

A  FRIEND  OF  MANY  AND   PLEASANT  YEARS 

A   BELOVED   TEACHER  AND   A 

GREAT  CHEMIST 

DE.  CHARLES  E.  MUNROE,  PH.D. 


609659 


INTRODUCTION 

THE  author's  "  Descriptive  Meteorology  "  (Ap- 
pleton,  1914)  is  designed  for  the  teaching  of  those 
who  intend  to  make  Meteorology  a  profession.  This 
book  is  planned  for  the  reading  of  those  who  desire 
to  know  something  of  the  wonders  of  the  New  Air 
World  into  which  man  is  just  now  entering,  for  those 
who  desire  to  become  weatherwise  and  make  fore- 
casts for  themselves,  and  to  apply  their  knowledge 
to  their  business,  their  health,  and  their  happiness ; 
and  for  the  reading  of  the  more  advanced  pupils  of 
the  public  schools. 

So  far  as  possible  technical  terms  are  avoided  and 
an  effort  made  to  tell  a  simple  story  that  will  awaken 
curiosity  and  lead  the  reader  to  wish  to  know  more 
and  more  of  the  mysteries  of  the  atmosphere,  of 
which  practically  nothing  was  known  at  the  time 
of  the  landing  of  the  Pilgrims,  Torricelli  not  hav- 
ing discovered  the  barometer  until  twenty-three 


viii  INTRODUCTION 

years  later.  It  will  be  made  plain  how  atmospheric 
air  was  formed,  how  long  it  will  remain,  whither 
it  will  go,  how  it  is  heated,  cooled,  and  lighted ; 
where  and  how  storms,  cold  waves,  clouds,  frosts, 
and  fair-weather  conditions  originate  and  how 
move ;  how  the  cyclone,  the  tornado,  and  the  thun- 
derstorm may  be  recognized  on  the  Daily  Weather 
Map  of  the  Government  and  their  future  activities 
forecast;  how  a  fund  of  simple  yet  wonderful  in- 
formation that  will  be  of  inestimable  value  may 
be  acquired  by  any  intelligent  person. 

The  author  acknowledges  courtesies  extended  to 
him  by  Prof.  Charles  F.  Marvin,  present  chief  of 
the  Weather  Bureau,  and  by  R.  H.  Weightman, 
chief  clerk  of  the  Bureau,  in  the  matter  of  securing 
several  important  illustrations;  and  like  favors 
extended  to  him  by  D.  Appleton  and  Company, 
John  Wiley  &  Sons,  and  the  Taylor  Instrument 
Company,  of  Rochester,  N.  Y. 

W.  L.  M. 

AUGUST,  1922 


CONTENTS 

CHAPTEB  PAGE 

INTRODUCTION vii 

I    ATMOSPHERES  OF  THE  EARTH,  THE  SUN,  AND  THE 

PLANETS 1 

n    A  SYNOPTIC  PICTURE  OF  THE  AIR         .        .        .  7 
HI    EXPLORATIONS  OF  THE  ATMOSPHERE      .        .        .18 

IV    EARTH'S  FOUR  ATMOSPHERES         ....  29 

V    LIGHT,  HEAT,  AND  TEMPERATURE          ...  48 
VI    THE  ADVANTAGE  OF  TAKING  WEATHER  OBSERVA- 
TIONS AND  APPLYING  THEM  TO  ONE'S  PERSONAL 

NEEDS         »        .        .        .       , .        .        .        .  64 

Vn    FROST     .     ,  .        .        ,        .       ...  '    .        ,        .  85 

VIII    WIND  AND  PRESSURE  OF  THE  GLOBE    ...  98 
IX    How  TO  FORECAST  FROM  THE  DAILY  WEATHER 

MAP    .        „  --     . .    .  i        .     .....       .        .        .  112 

:  X    CLIMATE          .        .        .        .        .        .        .        .161 

XI    How  CLIMATE  Is  MODIFIED  AND  CONTROLLED     .  188 

XII    CIVILIZATION  FOLLOWS  THE  STORM  TRACKS  .        .  218 

XIII  HAS  OUR  CLIMATE  CHANGED?      .        -.'      .•       .  225 

XIV  CLIMATES  FOR  HEALTH  AND  PLEASURE         .        .  245 
XV    CONDENSATION       .        *        .        *       *       y       .  282 

XVI    DEVELOPMENT  OF  THE  AMERICAN  WEATHER  SERV- 
ICE     *       „      v       ....      >       .  291 
INDEX  307 


LIST  OF  FIGURES 

Instrument  Shelter  (Figure  4)     .        .        .        .        Frontispiece 

FIQUKB  PAGE 

1.  Winter  and  Summer  Vertical  Temperature  Gradients, 

in  degrees  Centigrade  and  Fahrenheit      .         .         .12 

2.  Showing  light  from  lamp  a  passing  into  dust-free  air  at 

6,  and  passing  out  at  c  without  illuminating  the  in- 
terior         46 

3.  Standard  Weather  Bureau  Kite 64 

5.  Comparison  of  the  Thermometer  Scales       .        .        .67 

6.  Dry  and  Wet  Bulb  Thermometers       .        .        .        .68 

7.  Mercurial  Barometer 78 

8.  Continuous  records  of  the  temperature  from  4  P.M. 

to  9A.M. .'*'•.      87 

9.  Continuous  records  of  the  temperature  5  feet  and  35 

feet  above  ground  on  a  tower  in  a  pear  orchard       .       95 

10.  Average  dates  of  last  killing  frost  in  Spring         .         .96 

11.  Average  dates  of  first  killing  frost  in  Fall    ...       97 

12.  Trade  wind  circulation 99 

13.  Average  surface  winds  and  pressure  of  the  globe          .     102 

14.  How  winds  would  blow  into  a  cyclone  on  a  non-rotating 

earth        .         .        .    .    v 108 

15.  Deflection  of  wind  due  to  earth's  rotation  .        .        .     109 

16.  Annual,  summer,  and  winter  wind    velocities    with 

altitude    .        ...        .        .        .        .        .110 

17.  Tornado  Cloud 145 

18.  The  St.  Louis  Tornado  of  May  27,  1896,  Shot  a  Pine 

Scantling  through  the  Iron  Side  of  the  Eads  Bridge     147 

19.  The  St.  Louis  Tornado  of  May  27, 1896,  Shot  a  Shovel 

Six  Inches  into  the  Body  of  a  Tree  .        .        .        .147 

20.  The  St.  Louis  Tornado  Drove  Straws  One-half  Inch 

into  Wood  149 


xii  LIST  OF  FIGURES 

FIGURE  PAGE 

21.  Equinoxes,  March  21  and  September  22      ...     163 

22.  Summer  Solstice,  June  21    ...         .         .         .         .164 

23.  Winter  Solstice,  December  21 164 

24.  Winter  and  Summer  Solstices,  and  the  Equinoxes        .     165 

25.  As  angle  of  incidence  decreases  from  90°  to  10°  the  heat 

received  on  upper  end  of  blocks  is  spread  over  greater 
area  at  bottom,  and  its  temperature  diminished       .     165 

26.  Altitude  attained  by  Sun  at  midday  and  length  of  its 

track  above  the  horizon  at  the  Summer  and  Winter 
Solstices  and  at  the  two  Equinoxes  .         .         .         .167 

27.  Summer  day  and  Summer  night  temperatures  in  the 

same  narrow  valley 204 

28.  Average  Monthly  Temperature  and  Rainfall  of  Typical 

Places  in  North  America .        .        ...        .     .  ••        .     207 

29.  Average  Monthly  Temperature  and  Rainfall  of  Typical 

Places  in  the  Old  World  .         .        ,        .         .         .     208 

30.  Changes  in  Climate  in  California  during  the  Christian 

Era.         .        .        .        .    '".  •      .        .        ,.,     .     237 

31.  Snow  Crystals     ..       .     ,  .  ..    ."  .     .        «\    .        .    286 


LIST  OF  CHARTS 

CHART  PAQB 

1.  High  and  Low  Centers  of  Action  and  Prevailing  Winds 

of  the  Globe  for  July        .      V.      •         .         .         .99 

2.  High  and  Low  Centers  of  Action  and  Prevailing  Winds 

of  the  Globe  for  January 100 

3.  Winter  Storm,  December  15,  1893,  8  A.M.  .         .  114 

4.  Winter  Storm,  December  15,  1893,  8  P.M.  .         .  116 

5.  Winter  Storm,  December  16,  1893,  8  A.M.  .        .  118 

6.  Cold  Wave  Zones,  March  to  November.     Amount  of 

Fall  and  Verifying  Limit          .        .        .         .         .127 

7.  Cold  Wave  Zones,  December,  January,  and  February. 

Amount  of  Fall  and  Verifying  Limit        .         .         .128 

8.  Lowest  Temperatures  in  the  United  States,  1871-1913     129 

9.  Number  of  Cold  Waves,  1904-1914,  Inclusive     .         .     130 

10.  Storm  Tracks  for  August  for  Ten  Years      ,        .         .132 

11.  Storm  Tracks  for  February  for  Ten  Years  .     »   .         .134 

12.  Average  Maximum  Temperature  for  July   .        .        .     195 

13.  Ocean  Currents   .     *'..-.      .        .        *        .        .         .     196 

14.  Mean  Annual  Isotherms      .     '   .        .        .        *        .     200 

15.  Normal  Wind  Direction  and  Velocity  for  January  and 

February          .        ./ 202 

16.  Normal  Wind  Direction  and  Velocity  for  July  and 

August     .        .        .        .        .        .        •        .         .     204 

17.  Map  of  Climatic  Energy      .         .        ...-.,..'       .     221 

18.  Density  of  Population  in  the  United  States,  1910        .    222 


THE  NEW  AIR  WORLD 

CHAPTER  I 

ATMOSPHERES  OP  THE  EARTH,  THE  SUN, 
AND  THE  PLANETS 

How  Atmospheres  Are  Formed.  Once  there  were 
no  such  things  on  the  earth  as  hills  and  mountains, 
singing  brooks,  roaring  rivers  and  vast  oceans ;  and 
the  delicately  hued  landscape,  with  its  winding  roads, 
hedges,  flowers,  green  fields,  and  golden  grain,  had 
not  evolved  from  the  atmosphere.  The  earth  had 
not  yet  cooled  down  to  the  condition  of  a  solid  crust, 
everything  that  the  eye  now  sees  existed  in  the  form 
of  invisible  gases,  or  as  clouds  incandescent  with 
white  heat.  Fiery  blasts  swirled  over  the  face  of 
the  earth.  Storms  a  million  times  more  powerful 
than  the  most  destructive  West  Indian  hurricane  of 
the  present  day  moved  through  the  indescribably 
hot  atmosphere,  throwing  down  not  rain  as  we  under- 


£  THE  NEW  AIR  WORLD 

stand  it,  but  liquid  earth  and  metal,  as  their  rising 
clouds  ascended  and  cooled.  It  is  difficult  for  the 
human  mind  to  grasp  the  wonders  of  this. 

Small  planets  cool  quicker  than  large  ones  and 
sooner  come  to  the  conditions  of  a  crust  and  to  a 
temperature  suitable  for  the  development  of  the 
various  forms  of  life. 

Atmosphere  of  the  Sun.  To  the  unaided  eye  it 
appears  as  a  smooth,  bright,  quiescent  sphere,  but 
the  telescope  reveals  millions  of  agitations  and  hun- 
dreds of  red  flames  that  shoot  outward  to  distances 
of  hundreds  of  thousands  of  miles.  One  can  form 
no  adequate  picture  of  the  convulsions  of  the  atmos- 
phere of  the  sun.  During  eclipses,  when  the  intense 
glare  of  its  center  is  obscured,  hydrogen  flames  may 
be  seen  darting  outward  for  as  much  as  a  million 
miles. 

Lifeless  Planets.  The  larger  a  planet  the  longer 
is  the  time  that  must  elapse  before  the  hot  vapors 
of  rock  and  metal,  which  largely  compose  its  early 
atmosphere,  cool  and  congeal  into  a  crust,  leaving  as 
a  residual  an  atmosphere  of  such  heat,  density,  and 
composition  as  to  permit  of  the  beginnings  of  the 
forms  of  life  that  have  inhabited  the  world.  Before 
the  sun  can  reach  this  condition,  an  indescribable 
period  will  have  elapsed,  its  light  will  have  gone  out, 


ATMOSPHERES  OF  THE  EARTH         3 

its  heat  will  have  ceased  to  reach  the  earth  and  the 
other  planets  in  quantities  sufficient  to  maintain 
life,  the  earth  will  have  been  dead  millions  of  years, 
and  the  sun  itself  will  only  receive  heat  and  light 
from  the  feeble  rays  of  the  stars  that,  unlike  itself, 
have  not  yet  ceased  to  shine.  But  even  then  the  sun 
ever  must  remain  dead,  for  there  is  no  external  source 
whence  it  may  receive  heat.  No  vegetation  can 
adorn  it,  no  water  flow  upon  its  surface,  neither  can 
the  foot  of  any  man  press  its  soil. 

Jupiter,  and  perhaps  Neptune,  Uranus,  and  Saturn, 
have  hot  atmospheres  still  in  violent  agitation,  — 
molten  surfaces  composed  of  all  kinds  of  matter, 
from  which  bubble  and  boil  off  hot  clouds  of  vapor 
that  surge  about  in  huge  eddies  or  cyclonic  storms,  and 
that  here  and  there  are  shot  outward  in  tongues  of 
fire.  The  earth  millions  of  years  ago  had  a  similar 
atmosphere.  But  when  the  heat  energy  of  these 
vaporous  planets  wanes,  and  they  cool  down,  as~the 
earth  did  many  years  ago,  the  simplest  forms  of  life 
cannot  be  evolved  upon  them,  for  they  are  too  far 
away  from  the  sun  to  receive  life-giving  heat.  Mars 
receives  less  than  half  the  intensity  of  the  solar  rays 
that  come  to  the  earth,  Jupiter  only  0.037,  Saturn 
0.011,  Uranus  0.003,  and  Neptune  0.001. 

In  due  time  —  some  hundreds  of  millions  of  years 


4  THE  NEW  AIR  WORLD 

—  the  cooling  of  the  sun  will  leave  the  earth  to  freeze 
and  all  life  to  become  extinct,  unless,  perchance, 
the  oxygen  of  the  air  is  so  far  absorbed  by  its  rocks, 
or  filtered  away  into  space,  as  to  destroy  life  before 
that  time.  No  matter  what  may  be  the  achieve- 
ments of  the  human  mind,  what  wonderful  civiliza- 
tions may  be  developed,  what  powerful  empires 
created,  or  what  wonderful  secrets  of  creation  dis- 
covered, it  seems  certain  that  these  all  will  pass  away, 
and  finally  the  surface  of  the  earth  be  as  if  man  never 
lived.  The  dust  of  ages  will  wipe  out  and  obliterate 
every  trace  and  vestige  of  the  operations  of  life. 
Silence,  cold,  and  darkness  will  then  reign  supreme. 
But  the  time  of  this  is  indescribably  far  off  in  the 
future,  and  man  will  have  ample  opportunity  to  de- 
velop to  the  highest  mental  and  spiritual  estates  of 
which  he  has  inherent  possibilities. 

The  moon  already  is  dead.  If  it  is  formed  of 
matter  abandoned  by  the  earth,  as  we  believe,  it 
once  must  have  had  an  atmosphere,  a  portion  of 
which  was  absorbed  by  its  rocks  as  it  cooled,  and  the 
remainder  lost  as  the  result  of  the  low  power  of  at- 
traction of  so  small  a  body,  which  is  insufficient  to 
prevent  the  darting  molecules  of  the  gases  of  its  air 
from  shooting  off  into  space.  The  absence  of  an 
atmospheric  covering  allows  the  heat  from  the  sun  to 


ATMOSPHERES  OF  THE  EARTH         5 

escape  almost  as  rapidly  as  it  is  received ;  and  the 
long  nights  of  the  moon  (each  as  long  as  fourteen 
of  our  days)  during  which  the  sun's  rays  are  entirely 
cut  off,  permit  the  temperature  of  the  dark  side  to  fall 
to  something  like  -400°  F. 

How  Atmospheres  Are  Maintained  and  How 
Lost.  The  processes  of  nature  are  always  adding  to 
the  various  gases  of  the  atmosphere  in  some  ways, 
and  transforming  or  taking  from  them  in  other  ways. 
On  the  earth  the  loss  and  the  gain  are  so  nearly 
equal  as  to  maintain  at  present  a  nearly  constant 
condition.  Marked  changes  have  taken  place,  how- 
ever, in  long  geologic  periods.  Our  early  atmos- 
phere probably  contained  large  quantities  of  carbon 
dioxide  which  were  absorbed  by  the  rank  vegetable 
growth  that  now  forms  the  coal  beds  of  the  earth, 
and  the  slowly  cooling  rocks  that  constitute  the 
crust  took  in  large  quantities  of  oxygen;  in  fact, 
nearly  one  half  of  the  weight  of  the  crust  of  the 
earth  is  composed  of  the  latter  element.  >  | 

In  consequence  it  may  be  said  that  our  present 
atmosphere  is  what  remained  after  the  earth  had 
absorbed  its  gases  nearly  to  depletion,  and  after 
the  lighter  gases,  like  hydrogen  and  helium,  which 
seem  to  have  too  great  molecular  velocity  to  be 
imprisoned  by  the  earth's  attraction  of  gravitation, 


6  THE  NEW  AIR  WORLD 

had  been  lost  in  space.  Gases  that  cannot  be  held 
by  the  moon  may  be  imprisoned  by  the  earth  and 
those  that  can  escape  from  the  earth  may  be  held 
by  the  larger  planets. 

Height  of  the  Earth's  Atmosphere.  Exact  com- 
putation has  shown  that  if  the  air  were  the  same 
density  at  all  elevations,  which  it  is  not,  it  would 
extend  upward  a  distance  of  only  five  miles.  From 
laws  that  are  well  understood  it  is  known  that  at  a 
height  of  thirty  miles  the  atmosphere  is  only  about  one 
hundredth  as  dense  as  it  is  at  the  surface  of  the 
earth,  and  that  at  fifty  miles  it  is  too  light  to  mani- 
fest a  measurable  pressure.  The  oxygen  ceases 
at  about  thirty  miles  and  the  nitrogen  at  about 
fifty  miles,  the  water  vapor  being  restricted  below 
the  five-mile  level.  The  appearance  of  meteors, 
which  are  rendered  luminous  by  rushing  into  the 
earth's  atmosphere,  and  whose  altitudes  have  been 
determined  by  simultaneous  observations  at  several 
stations,  reveals  the  presence  of  hydrogen  and  helium 
at  a  height  of  nearly  two  hundred  miles. 


CHAPTER  II 
A  SYNOPTIC  PICTURE  OF  THE  AIR 

How  much  do  you  know  of  the  great  aerial  ocean 
on  the  bottom  of  which  you  live  and  in  which  human 
beings  are  just  beginning  to  fly?  Its  variations  of 
heat,  cold,  sunshine,  cloud,  and  tempest  materially 
affect  not  only  the  health  and  happiness  of  man 
but  his  commercial  and  industrial  welfare,  and  yet 
few  know  more  than  little  of  the  wonders  of  the 
life-giving  medium  that  so  intimately  concerns 
them. 

At  the  Height  of  Two  Hundred  Miles.  Here  is 
only  the  invisible,  the  intangible  ether  which,  while 
too  tenuous  to  be  detected  or  measured  by  any 
appliances  of  man,  is  supposed  to  transmit  the  rays 
of  the  sun.  These  rays,  coming  in  the  form  of  many 
different  wave  lengths,  and  with  widely  differing 
velocities  of  vibration,  produce  a  multitude  of  phe- 
nomena as  they  are  absorbed  by  or  pass  through 
the  air,  or  as  they  reach  the  surface  of  the  earth. 


8  THE  NEW  AIR  WORLD 

The  longer  and  slower  waves  are  converted  into  heat, 
the  shorter  and  more  rapid  ones  into  light,  and  the 
minutest  movements  probably  into  electricity. 

Oxygen  and  nitrogen,  which  form  the  greater 
part  of  the  atmospheric  gases,  absorb  comparatively 
little  of  the  solar  rays,  while  water  vapor,  which 
constitutes  a  little  more  than  one  per  cent,  of  the 
atmosphere  and  which  remains  close  to  the  earth, 
absorbs  large  quantities.  From  the  fact  that  one 
half  of  the  atmosphere,  including  nearly  all  of  its 
water  vapor,  lies  below  an  elevation  of  three  and 
one  half  miles,  it  becomes  evident  that  the  greater 
part  of  the  absorption  of  the  sun's  rays  must  take 
place  in  the  lower  strata.  On  clear  days  the  atmos- 
phere absorbs  nearly  one  half  of  the  sun's  heat  rays ; 
the  remainder  reaches  the  surface  of  the  earth,  warms 
it  and  in  turn  is  radiated  back  into  the  air,  —  with 
this  difference :  that  as  earth  radiation  the  wave 
motion  of  the  rays  is  longer  and  slower  than  it  was 
when  the  rays  entered  our  atmosphere  as  solar  ra- 
diation. In  this  slower  form  the  rays  are  the  more 
readily  absorbed.  The  atmosphere  is  thus  warmed 
largely  from  the  bottom  upwards,  which  accounts 
for  the  perpetual  freezing  temperatures  of  high 
mountain  peaks,  although  they  are  nearer  the  sun 
than  are  the  bases  from  which  they  rise. 


A  SYNOPTIC  PICTURE   OF  THE  AIR    9 

At  the  Height  of  One  Hundred  Miles.  The  tem- 
perature at  this  altitude  must  be  that  of  outside  space, 
probably  459°  F.1  below  zero.  Air  liquefies  at  312° 
below,  and  therefore  it  cannot  exist  in  the  gaseous 
state  in  a  region  having  a  lower  temperature.  When 
it  liquefies  it  has  the  color  and  general  appearance 
of  water,  and  about  the  same  specific  gravity. 

When  a  piece  of  steel  and  a  lighted  taper  are 
brought  together  inside  of  a  vessel  filled  with  liquid 
air,  the  dense  supply  of  oxygen  makes  combustion 
so  rapid  that  the  hard  metal  burns  like  tinder. 

At  the  Height  of  Fifty  Miles.  There  is  enough 
air  here  to  refract  light  slightly,  as  at  twilight,  and  to 
render  luminous  the  meteors  that  rush  with  fearful 
velocity  against  its  widely  scattered  molecules.  At 
this  distance  from  the  earth  there  probably  is  no 
more  air  than  would  be  found  under  the  receiver  of 
the  best  air  pump,  and,  the  reader  will  be  surprised 
to  learn,  darkness  is  practically  complete,  although 
the  hour  may  be  midday,  for  there  are  no  dust  motes 
to  scatter  and  diffuse  and  render  visible  the  light 
rays  of  the  sun.  (See  Chapter  III.) 

The  Darkness  of  Outer  Space.  It  may  be  proven 
by  taking  an  inclosed  volume  of  air,  freeing  it  of 

1  Unless  otherwise  expressed  in  this  book  it  will  be  understood  that  all 
temperatures  are  recorded  by  the  Fahrenheit  scale. 


10  THE   NEW  AIR  WORLD 

dust  motes,  of  which  there  are  millions  per  cubic 
centimeter,  and  then  trying  to  illuminate  it ;  it  will 
be  found  that  no  matter  how  powerful  the  light 
directed  into  it,  it  remains  wholly  dark.  When  one 
looks  upward  on  a  clear  day,  he  apparently  sees  the 
whole  universe  illuminated;  but  in  point  of  fact 
only  the  thin  stratum  of  the  earth's  air  in  which 
he  lives  is  illuminated.  Outer  space  is  practically 
without  temperature  or  light.  The  rays  of  the  sun 
do  not  become  either  light  or  heat  or  electricity 
until  they  encounter  the  molecules  of  the  air,  or  the 
invisible  dust  motes,  or  the  cloud  particles  near 
the  earth  and  through  interference  are  transmuted 
from  etheric  vibrations  into  other  forms  of  energy. 

The  Bacteria  of  Disease  and  of  Putrefaction. 
These  rapidly  diminish  in  number  with  elevation, 
and  on  the  tops  of  the  highest  mountain  peaks 
practically  none  are  found.  Mid-ocean  also  shows 
but  few. 

At  the  Height  of  Twenty-five  Miles.  Air,  light 
as  it  is,  has  still  sufficient  density  to  obstruct  the 
passage  of  the  minutest  wave  lengths  of  light,  and 
here  probably  begins  to  be  appreciable  the  blue  tint 
of  the  heavenly  vault.  At  this  short  distance  from 
the  earth  there  must  be  a  deathlike  stillness,  for 
there  is  no  medium  sufficiently  dense  to  transmit 


A  SYNOPTIC  PICTURE  OF  THE  AIR    11 

sound.  Two  persons  could  not  hear  each  other 
speak,  even  if  they  could  live  in  this  rare  atmos- 
phere, which  they  could  not.  Here  is  eternal  peace 
and  no  apparent  motion,  for  storms  and  ascending 
and  descending  currents  cease  long  before  this  level 
is  reached.  The  cold  is  intense  and  daylight  but  a 
feeble  illumination.  There  are  no  clouds. 

Isothermal  Stratum  Entered  at  the  Height  of 
Seven  Miles.  We  know  that  the  temperature 
decreases  rapidly  with  ascent  —  about  one  degree 
for  each  three  hundred  feet  —  until  the  top  of  the 
storm  level  is  reached,  at  about  seven  miles,  when 
a  most  wonderful  discovery  is  made :  the  thermom- 
eter no  longer  falls  as  the  aviator  rises,  or  as  balloons 
float  to  great  altitudes  carrying  self-registering 
instruments.  The  temperature  remains  practically 
stationary,  so  far  as  exploration  has  been  made, 
which  is  to  the  height  of  over  nineteen  miles.  Major 
R.  W.  Schroeder,  U.  S.  A.,  flew  in  an  aeroplane  to 
36,000  feet  and  recorded  a  temperature  of  69°  below 
zero. 

We  have  named  this  region  above  storms  the 
Isothermal  stratum.  (See  Figure  1.)  Its  temperature 
everywhere  is  about  70°  below  zero  and  it  changes 
only  about  six  degrees  between  winter  and  summer. 
Of  course  we  must  assume  that  ultimately  the 


THE  NEW  AIR  WORLD 


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FIG.  1 . — Winter  and  Summer  Vertical  Temperature  Gradients,  in  degrees 
Centigrade  and  Fahrenheit. 

temperature  shades  away  to  practically  nothing  as 
outer  space  is  reached. 

Scientific  and  inventive  genius  is  becoming  so 
skillful  in  harnessing  the  forces  of  nature  to  man's 
desires  that  it  is  reasonable  to  anticipate  that  within 
a  quarter  of  a  century  or  less  human  beings  will  be 


A  SYNOPTIC  PICTURE  OF  THE  AIR    13 

nearly  as  numerous  in  the  air  as  insects,  they  will 
remain  aloft  longer,  and  sail  to  vastly  greater  dis- 
tances and  to  higher  altitudes.  In  time  dirigible  ships 
may  sail  for  days  and  possibly  for  weeks  in  the  pure 
air  aloft,  carrying  millions  of  passengers. 

At  a  Height  of  One  and  One  Half  Miles.  There 
is  little  difference  in  the  temperatures  of  day  and 
night,  except  that  the  coolest  time  of  the  twenty- 
four  hours  is  during  daytime  and  not  at  night,  as 
would  be  most  naturally  supposed.  This  is  im- 
portant inform  ion  to  an  aviator  or  to  the  pilot 
of  a  balloon. 

At  an  Altitude  of  One  Thousand  Feet.  In  free 
air  at  the  hottest  time  in  midsummer's  heat,  the  air 
is  found  to  be  as  much  as  fifteen  degrees  lower  than 
that  at  the  ground.  Almost  within  arm's  length 
of  the  streets  of  great  inland  cities  there  is  a  cool 
and  healthful  atmosphere  when  humanity  is  swelter- 
ing and  dying  from  heat  below.  Some  youth  who 
is  reading  this  may  develop  the  genius  that  will 
lift  up  whole  city  blocks  into  this  cool  and  healthful 
region.  Open  steel  work  below,  the  first  level  at 
one  or  two  thousand  feet  above  the  hot  streets, 
express  elevators  to  carry  passengers,  and  the  climate 
of  the  cool  mountain  air  is  accessible  to  those  who 
now  live  in  discomfort  at  low  populous  centers. 


14  THE  NEW  AIR  WORLD 

Man  is  just  beginning  to  disport  himself  in  the 
hitherto  trackless  wilderness  of  the  air.  Certain 
it  is  that  the  hanging  gardens  of  Babylon  will  be 
outdone  in  the  Twentieth  Century  and  the  eyrie  of 
the  eagle  left  far  below  by  those  who  will  live  a  part 
of  their  time  in  elevated  structures  having  bases 
resting  upon  the  earth;  or  who  will  fly  to  great 
distances  aloft  and  remain  at  whatever  altitude 
furnishes  them  the  most  pleasant  and  beneficial 
conditions,  and  that  they  may  thus  remain  not  only 
for  days  but  for  weeks  without  returning  to  the 
surface  of  the  earth. 

Only  during  recent  years  have  we  realized  how 
thin  is  the  stratum  of  air  next  to  the  earth  which 
has  sufficient  heat  and  moisture  for  the  inception, 
growth,  and  maturity  of  animal  and  vegetable  life. 
The  raising  of  the  instrument  shelter  at  the  New 
York  station  of  the  U.  S.  Weather  Bureau  from  an 
elevation  of  one  hundred  and  fifty  feet  above  the 
street  to  an  altitude  of  three  hundred  feet  has  caused 
an  apparent  lowering  of  the  mean  annual  temper- 
ature of  two  and  one  half  degrees. 

Air  is  so  elastic  and  its  density  diminishes  so 
rapidly  with  elevation  that  nearly  one  half  of  the 
weight  of  the  entire  mass  of  the  atmosphere  lies  be- 
low the  level  of  the  top  of  Pike's  Peak,  which  has  a 


A  SYNOPTIC  PICTURE  OF  THE  AIR    15 

height  of  a  little  less  than  three  miles  above  sea  level. 
It  presses  with  a  weight  of  about  fifteen  pounds  per 
square  inch  of  surface,  and  its  pressure  is  exerted 
in  all  directions,  upward  as  well  as  downward.  An 
ordinary  man  sustains  a  pressure  of  over  one  ton  on 
each  square  foot  of  his  surface,  but  as  the  air 
penetrates  all  portions  of  his  body  and  exercises  a 
pressure  outward  as  well  as  inward  he  feels  no 
inconvenience.  If  his  body  could  be  so  tightly 
sealed  that  no  air  could  enter  and  if  then  the  air  of 
the  interior  should  be  removed  with  a  pump,  his 
body  instantly  would  be  crushed  to  a  shapeless 
pulp. 

A  cubic  foot  of  atmospheric  air  weighs  one  and 
one  third  ounces.  Water  is  773  times,  and  mercury 
ten  thousand  times,  as  dense  as  air.  But  air  is  a 
more  ponderable  substance  than  many  suppose ;  an 
ordinary  lecture  hall  forty  by  fifty  feet  and  thirty 
feet  from  floor  to  ceiling  contains  two  and  one  half 
tons  of  air  at  freezing  temperature.  It  would 
contain  less  at  a  higher  temperature,  because  heat 
expands  its  volume;  it  would  contain  more  at  a 
lower  temperature,  because  cold  contracts  its  volume. 

Everything  Evolved  from  the  Air.  Air  is  so  com- 
mon that  we  seldom  stop  to  consider  the  magnitude 
of  the  force  it  exerts  or  the  grandeur  wrought  by 


16  THE  NEW  AIR  WORLD 

this  invisible  architect  of  nature.  In  the  great  cycle 
of  world  building  —  birth  from  the  nebulae,  growth, 
maturity,  decay,  disintegration,  death,  and  then 
possibly  back  again  to  the  nebulae  —  the  atmos- 
phere, be  it  light  and  tenuous  as  at  present,  or  be 
it  filled  with  the  hot  vapors  of  earth  and  metal,  is 
the  vehicle  and  the  medium  of  the  builder,  trans- 
porting and  transmuting,  in  mysterious  ways  and 
to  wondrous  forms,  the  materials  of  planets.  Its 
work  as  a  builder  may  be  further  illustrated  by 
showing  that  the  body  of  man  itself  returns  not  to 
the  earth  earthy,  as  we  have  been  taught,  but  largely 
to  the  air  whence  it  came.  Decomposition  is  but 
the  liberation  of  the  aeriform  gases  of  which  it  is 
mainly  composed ;  the  residue  is  but  a  handful  that 
goes  back  to  mother  earth.  Let  us  take  the  dried 
corn  plant ;  weigh  it,  then  burn  it  in  a  closed  vessel 
so  that  none  of  the  ashes  can  blow  away.  Continue 
the  burning  until  the  ashes  are  perfectly  white  and 
it  will  be  found  that  the  weight  of  the  ashes  is  only 
about  one  twentieth  of  the  weight  of  the  great  stalk, 
ear,  and  foliage  we  began  with.  What  has  become 
of  all  the  rest?  The  fire  has  destroyed  it,  you  say. 
No,  we  can  destroy  nothing.  Remember  that; 
we  can  destroy  nothing  that  the  Creator  has  made, 
neither  matter  nor  force.  The  fire  has  simply 


A  SYNOPTIC  PICTURE  OF  THE  AIR    17 

changed  the  form  of  the  plant;  the  nineteen  twen- 
tieths that  have  disappeared  have  gone  back  to  the 
air  whence  they  came. 

Thus  we  see  that  the  body  of  man,  the  cereal  and 
fruit  that  furnish  him  food,  the  structure  that  gives 
him  shelter,  aye,  the  many  things  that  please  the 
eye :  the  landscape,  the  beautiful  flowers,  the  green 
fields,  the  babbling  brooks,  even  the  rose  blush  on 
the  maiden's  cheek,1 — really  come  from  this  wonder- 
ful fluid  surrounding  the  earth,  and  well  may  it  be 
said  that  the  queen  of  life  rides  upon  the  crest  of  the 
wind. 

1  The  author  wishes  that  this  were  literally  true,  for  he  believes  that 
no  great  man  or  great  woman  ever  was  born  from  a  mother  with  a  painted 
face,  dyed  lips,  false  hair,  and  a  body  pitifully  distorted  by  ungracefully 
ambling  about  in  high  heeled  shoes.  The  power  of  suggestion  is  so  great 
in  its  influence  on  the  plastic  mind  of  youth  that  a  mother  who  is  little 
else  than  a  perambulating  falsehood  will  leave  descendants  wanting  in 
many  if  not  all  of  the  attributes  of  manly  and  womanly  virtues. 


CHAPTER  III 
EXPLORATION  OF  THE  ATMOSPHERE 

DISCOVERIES     AS    VALUABLE    TO    THE     FUTURE    AS     THOSfl 
MADE   BY   COLUMBUS 

AN  entire  new  world  is  coming  within  the  range 
of  man's  vision.  Its  possibilities  for  adding  to  the 
health  and  happiness  of  mankind  are  almost  limit- 
less. The  geographic  poles  have  been  conquered 
and  the  jungles  of  Africa  traversed ;  and  deep  borings 
have  been  made  into  the  bowels  of  the  earth  until 
heat  has  arrested  further  progress.  The  further 
exploration  of  both  regions  is  of  the  utmost  im- 
portance to  the  coming  age.  It  is  not  at  all  visionary 
to  assume  that  the  heat  of  the  earth's  interior  in 
near  time  will  furnish  the  power  necessary  to  do  the 
drudgery  of  mankind,  give  warmth  and  light  to 
habitations,  and  operate  transportation  systems; 
and  the  New  World  Above  offers  pure,  electrified, 


EXPLORATION  OF  THE  ATMOSPHERE    19 

and  highly  stimulating  air  into  which  helium-in- 
flated dirigible  balloons  will  sail,  and  in  which  they 
will  remain  not  only  days  but  weeks  or  longer,  with 
their  multitudes  of  people. 

While  the  use  of  kites  and  balloons  in  sending 
automatic  meteorological  instruments  far  aloft  has 
revealed  more  of  the  wonders  of  this  hitherto  un- 
charted wilderness  of  cold  and  partial  or  total  dark- 
ness than  the  general  public  is  aware  of,  only  the 
outer  fringes  of  the  mysterious  regions  above  the 
clouds  and  the  storms  have  been  penetrated. 

When  the  manufacture  of  helium,  a  noncombus- 
tible  gas  almost  as  light  as  hydrogen,  becomes  more 
general,  as  seems  imminent  in  the  United  States, 
the  dirigible  balloon  may  successfully  compete  with 
the  railroads  in  the  carrying  of  long-distance  pas- 
sengers. The  recent  loss  of  over  forty  lives  in  Eng- 
land by  the  collapse  of  the  dirigible  ZR2  probably 
was  largely  if  not  entirely  due  to  the  explosion  and 
fire  of  the  hydrogen  gas  with  which  the  ship  was 
inflated. 

A  decade  ago,  in  a  number  of  Chautauqua  lectures, 
the  writer  invariably  was  greeted  with  looks  of  in- 
credulity when  he  prophesied  that  within  ten  years 
travelers  of  the  air  would  take  breakfast  at  the 
Waldorf-Astoria  in  New  York  and  afternoon  tea 


20  THE  NEW  AIR  WORLD 

on  the  banks  of  the  Thames.  And  yet  the  ocean 
already  has  been  crossed  by  an  aeroplane  in  con- 
tinuous flight,  and  in  the  near  future  it  is  highly 
probable  that  aerial  navigation  will  be  safer  than 
travel  by  rail  or  automobile.  The  hitherto  inac- 
cessible parts  of  the  earth  will  be  sailed  over  and 
closely  scrutinized,  while  travelers  enjoy  the  com- 
forts that  heretofore  have  been  associated  with 
Pullman  service. 

In  1862  the  English  meteorologist  Glashier  as- 
cended in  a  balloon  to  about  the  same  height  as  that 
attained  by  Major  R.  W.  Schroeder,  U.  S.  A.,  who 
achieved  a  more  difficult  feat  when  he  flew  in  an 
aeroplane  to  over  36,000  feet.  And  at  Dayton, 
Ohio,  celebrated  as  the  home  of  the  Wright  brothers, 
on  September  28,  1921,  Lieutenant  John  A. 
Macready,  U.  S.  A.,  reached  the  unprecedented 
height  of  40,800  feet.  These  are  the  extreme  alti- 
tudes to  which  human  beings  ever  have  attained, 
but  they  are  only  the  beginning  of  explorations  into 
a  vast  and 'largely  unknown  and  extremely  cold  re- 
gion, —  one  in  which  darkness  increases  with  ele- 
vation until  at  the  outer  limits  of  the  atmosphere  no 
illumination  whatever  exists. 

The  high  eastward  wind  and  69°  below  zero 
encountered  by  Schroeder  are  conditions  that  already 


EXPLORATION  OF  THE  ATMOSPHERE    21 

had  been  revealed  by  the  work  done  at  the  research 
station  of  the  Weather  Bureau,  at  Mount  Weather, 
Virginia,  and  at  other  stations  in  this  country  and 
in  Europe,  by  the  sending  up  of  instruments  unac- 
companied by  observers.  Under  the  direction  of 
the  writer  the  Weather  Bureau  liberated  numerous 
small  hydrogen  gas  balloons  in  the  Rocky  Mountain 
region,  to  which  were  attached  automatic  instru- 
ments registering  the  temperature,  pressure,  and  the 
hygrometric  conditions.  As  they  came  eastward 
in  the  atmospheric  drift  that  always  prevails  above 
the  storms  in  the  middle  latitudes  they  attained 
to  great  altitudes,  one  balloon  reaching  19.1  miles, 
the  greatest  altitude  ever  reached  at  that  time  by 
the  appliances  of  man.  Ultimately  the  balloons 
would  explode  as  they  expanded  under  the  influence 
of  decreasing  air  pressure  and  the  case  of  instruments 
would  descend  slowly  under  a  parachute  designed 
to  open  at  the  right  moment.  The  barometer 
traced  a  line  on  a  paper  cylinder  revolving  by  clock 
works,  as  did  the  thermometer.  The  thermogram 
gave  the  temperature  that  corresponded  with  the 
varying  elevation  shown  by  the  tracing  of  the  baro- 
gram. 

In  1898,  twelve  hundred  observations  were  made 
with  kites  by  the  observers  of  the  Weather  Bureau 


22  THE  NEW  AIR  WORLD 

at  seventeen  stations  selected  by  the  writer,  during 
the  six  warm  months  from  May  to  October.  It  was 
surprising  to  find  the  temperature  often  losing  as 
much  as  fifteen  degrees  with  the  first  thousand 
feet  ascent  during  middays  of  extremely  hot 
periods.  The  average  decrease  in  temperature  per 
thousand  feet  elevation  for  all  stations  for  all  times, 
and  at  all  elevations  up  to  5280,  was  4°. 

For  over  five  years  kites  were  used  nearly  every 
day  in  the  year  at  Mount  Weather  to  carry  instru- 
ments aloft  to  heights  ranging  from  two  to  four  and 
one  half  miles,  and  at  times  to  keep  the  apparatus 
up  during  all  hours  of  the  day,  so  that  a  comparison 
could  be  made  of  the  difference  between  day  and 
night  temperatures.  There  is  but  little  difference 
between  midday  and  midnight  at  only  a  few  thou- 
sand feet  above  the  earth. 

Few  are  aware  that  the  rectangular  kite  of  the 
weather  man  was  the  forerunner  of  the  aeroplane 
of  the  aviator.  In  1903,  while  directing  wireless 
experiments  in  the  sending  of  messages  at  Roanoke 
Island,  North  Carolina,  the  writer  saw  the  Wright 
brothers,  or  their  representatives,  lying  flat  upon 
the  lower  planes  of  what  appeared  to  be  Weather 
Bureau  kites  and  gliding  in  the  air  from  the  top  of 
the  sand  dunes.  This  was  the  beginning  of  real 


EXPLORATION  OF  THE  ATMOSPHERE    23 

flight  by  man.  The  ingenuity  of  the  Wrights  trans- 
formed the  weather  man's  kite,  strengthened  it,  took 
out  the  ends,  hitched  on  a  rudder,  and  when  the 
petrol  engine  had  developed  sufficient  power  with  a 
given  weight,  installed  it,  and  flew. 

In  the  future  the  meteorologist  and  the  aviator 
will  be  closely  associated.  With  a  sufficient  number 
of  weather  observations  made  by  aviators  simul- 
taneously and  well  distributed  over  the  United 
States  it  will  be  possible  to  construct  a  daily  weather 
map  on  some  high  level  —  say  the  three-mile  level 
—  similar  to  the  map  now  based  upon  sea  level. 
The  pressure,  temperature,  wind  direction,  clouds, 
and  rainfall  would  be  recorded  and  charted  for  the 
upper  region  clear  across  the  continent.  Three 
miles  is  about  halfway  to  the  top  of  cyclonic  storms 
and  probably  in  the  region  of  greatest  activity. 
More  accurate  forecasts  would  be  possible  by  the 
study  of  this  additional  weather  chart.  This  co- 
operation of  the  bird  man  and  the  weather  man  in 
studying  the  geography  of  the  new  air  world  will 
mark  an  epoch  in  meteorological  science  as  far- 
reaching  in  its  consequences  as  were  the  discovery 
of  the  barometer  by  Torricelli  and  the  uncovering 
of  the  principles  of  the  thermometer  by  Galileo, 
the  former  of  which  was  not  known  until  more  than 


24  THE  NEW  AIR  WORLD 

twenty-three  years  after  the  landing  of  the  Pilgrims 
at  Plymouth  Rock.  Thus  swiftly  does  the  mind  of 
man  to-day  explore  the  hidden  recesses  of  nature's 
mysteries,  and  with  each  conquest  carry  itself  to  a 
higher  realm  of  existence. 

In  the  not  distant  future,  more  storm  warnings 
may  be  issued  by  the  Weather  Bureau  for  ships  of 
the  air  than  for  those  of  the  sea,  for  the  navigation 
of  the  air  must  play  an  increasing  and  important 
part  in  the  coming  activities  of  the  world.  Science 
is  becoming  so  skilled  in  the  harnessing  of  the  forces 
of  nature  to  man's  desires  and  in  the  development  of 
mechanical  appliances,  that  it  is  reasonable  to 
anticipate  the  possibility  that  long-distance  travel 
over  land  or  ocean  ultimately  will  be  almost  entirely 
confined  to  the  air. 

As  the  result  of  the  explorations  of  the  atmos- 
phere made  by  the  institution  at  Mount  Weather 
there  was  ready  for  our  fighting  air  men  at  the  front, 
immediately  on  our  entry  into  the  World  War,  a 
fund  of  useful  information  concerning  a  region  that 
but  a  short  time  before  was  entirely  uncharted. 
The  instruments  carried  by  the  exploring  kites  and 
balloons  had  keen  scientific  eyes  and  they  recorded 
on  clock-timed  cylinders  what  they  saw.  Thus 
did  the  air  pilot  know  much  about  the  direction  and 


EXPLORATION  OF  THE  ATMOSPHERE    25 

the  force  of  the  wind  that  he  would  encounter  as  he 
rose,  the  altitude  where  he  would  pass  above  clouds, 
the  degree  of  cold  that  he  would  encounter,  etc.  He 
was  told  that  the  temperature  would  fall  about  one 
degree  for  each  three  hundred  feet  of  his  ascent  until 
he  reached  the  top  of  the  storm  stratum  at  six  or 
seven  miles,  and  that  if  he  could  reach  that  altitude 
he  would  observe  a  most  wonderful  phenomenon: 
the  temperature  no  longer  would  fall  with  gain  in 
altitude ;  he  would  enter  a  cold  but  an  equally  heated 
stratum,  without  finding  any  temperatures  lower 
than  were  encountered  upon  entering  the  region, 
which  is  always  about  seventy  degrees  below  zero. 

If  the  aerial  explorer  could  stop  his  ship  and  keep 
it  at  an  altitude  of  about  one  and  one  half  miles  for 
twenty -four  hours  he  would  be  startled  to  find  that 
the  coolest  time  of  the  period  was  during  the  day- 
time, not  during  the  night,  as  he  had  expected  to 
find  it. 

In  the  future  the  traveler  in  the  upper  reaches 
of  the  atmosphere  will  carry  oxygen  and  make  the 
kind  of  air  that  he  wishes  to  breathe,  and  he  will 
properly  protect  himself  against  the  cold  of  his  new 
world,  which  he  will  find  deficient  in  dust  motes  and 
doubtless  entirely  wanting  in  the  bacteria  of  putre- 
faction and  of  disease.  There  will  be  no  clouds  to 


26  THE  NEW  AIR  WORLD 

obscure  his  vision;  no  rain  or  snow.  He  will  not 
often  ascend  above  the  region  where  there  are  not 
some  dust  motes  to  scatter  and  diffuse  a  part  of  the 
solar  rays  and  give  him  at  least  a  partial  illumination. 
Few  persons  are  familiar  with  the  simple  problems 
of  the  air  which  have  such  important  bearing  on  the 
distribution  of  man  into  realms  above  those  he  has 
been  accustomed  to  occupy.  They  do  not  know 
that  the  northwest  wind  brings  physical  energy  and 
mental  buoyancy  because  it  has  a  downward  com- 
ponent of  motion  that  draws  air  from  above,  where 
it  is  free  of  impurities,  and  where  high  electrification 
has  changed  a  considerable  quantity  of  its  oxygen 
into  ozone,  in  which  condition  it  remains  but  a 
short  time  after  reaching  the  lower  potential  near 
the  earth's  surface.  More  people  die  under  the 
influence  of  the  south  wind  than  under  the  influence 
of  the  north  wind,  because  the  south  winds  hug  the 
surface  of  the  earth  and  become  laden  with  impuri- 
ties and  are  lacking  in  electrical  stimulation.  When 
inventive  man  becomes  more  familiar  with  the  ocean 
on  the  bottom  of  which  he  has  heretofore  lived,  he 
will  not  wait  for  the  north  wind  to  bring  down  to 
him  the  beneficial  conditions  that  always  exist  higher 
up ;  he  will  go  after  them  and  remain  aloft  as  long 
as  he  desires  to  do  so. 


EXPLORATION  OF  THE  ATMOSPHERE    27 

The  further  development  of  the  dirigible  balloon 
and  the  aeroplane  are  among  the  most  important 
duties  that  the  engineer  of  the  future  owes  to  civili- 
zation; and  the  meteorologist  must  establish  the 
climatology  of  the  vast  untracked  regions  above  the 
highest  mountain  peaks,  for  here  man  will  largely 
disport  himself  in  the  time  to  come. 

The  writer  agrees  with  the  opinion  of  Major 
William  R.  Blair,  formerly  of  his  staff  when  he  was 
the  head  of  the  U.  S.  Weather  Bureau,  but  since  the 
beginning  of  the  World  War  the  chief  meteorological 
assistant  of  the  Chief  Signal  Officer  of  the  U.  S.  Army 
when  he  says : 

"  With  reference  to  air  travel  in  the  future :  the 
present  stage  of  aircraft  development  seems  to 
indicate  that  long  non-stop  traffic,  both  freight  and 
passenger,  in  the  air  will  be  by  means  of  lighter- 
than-air  craft  (balloons).  These  craft  have  much 
larger  carrying  capacity  than  any  airplanes  now 
designed  and  will  travel  across  the  continent  over 
several  prepared  routes,  stopping  only  at  important 
centers  on  these  routes  to  discharge  and  take  up 
passengers  and  freight.  It  is  believed  that  airplanes 
(heavier-than-air  craft)  will  ply  between  these 
important  centers  and  the  outlying  country  about 
them,  thus  acting  as  feeders  to  the  main  route, 
over  which  the  monstrous  dirigibles  will  operate. 
Most  transoceanic  as  well  as  transcontinental  air 


28  THE  NEW  AIR  WORLD 

traffic  will  probably  be  carried  on  in  these  large  diri- 
gible balloons." 

Lieutenant  Colonel  Henry  B.  Hersey,  who  served 
through  the  World  War  in  the  Aeronautical  Service 
of  the  Signal  Corps,  U.  S.  A.,  and  who  also  was  as- 
sociated with  the  writer  in  the  management  of  the 
Weather  Bureau,  says : 

"  The  fields  of  the  dirigible  and  the  air  plane  are 
separate  and  there  is  no  conflict  between  the  two. 
For  light  loads,  great  speed,  and  quick  manceuver- 
ing,  the  airplane  is  supreme.  For  heavy  loads, 
long  distance,  ability  to  remain  in  the  air  for  great 
periods  of  time,  the  dirigible  is  the  only  air  craft 
that  can  fulfill  the  requirements.  Dirigibles  will 
soon  be  in  use  which  can  start  from  Europe,  sail  over 
New  York,  and  drop  enough  poison  gas  to  kill 
thousands  and  make  practically  the  whole  city  un- 
inhabitable." 


CHAPTER  IV 
EARTH'S  FOUR  ATMOSPHERES 

THE  earth  has  four  important  atmospheres  and 
others  of  less  importance.  The  principal  ones  are 
oxygen,  nitrogen,  vapor  of  water,  and  carbon  dioxide, 
each  comporting  itself  as  it  would  do  if  the  others 
were  not  present.  There  is  space  between  the  mole- 
cules of  each  gas,  and  therefore  it  is  easily  compressed. 
A  doubling  of  its  pressure  reduces  its  volume  one 
half. 

Composition  of  Atmospheric  Air.  It  is  difficult 
for  the  mind  to  form  a  picture  of  the  infinitely  small 
molecules  of  the  air.  Let  us  therefore  use  terms  and 
comparisons  that  will  the  more  directly  appeal  to 
the  human  senses.  First  let  us  imagine  each  mole- 
cule enlarged  to  the  size  of  a  small  grain  of  sand. 
Then  with  the  molecules  from  one  cubic  inch  of  air 
transformed  into  grains  of  sand  we  could  build  a 
roadway  ten  feet  deep  and  one  hundred  feet  wide 


30  THE  NEW  AIR  WORLD 

extending  from  New  York  to  San  Francisco.  May 
one  still  further  grasp  the  idea  of  the  atom,  many 
of  which  are  required  to  make  up  the  molecules  ?  If 
so,  the  imagination  has  been  stretched  to  its  limits 
to  enable  the  human  mind  to  comprehend  some  of 
the  simplest  facts  with  regard  to  the  wonderful 
fluid  in  which  we  live. 

Sir  William  Thomson,  afterwards  Lord  Kelvin, 
in  endeavoring  to  give  relative  values  that  would 
appeal  to  the  imagination,  said  that  if  a  drop  of 
water  were  enlarged  to  the  size  of  the  earth,  the 
molecules  of  which  it  is  composed  would  be  no 
larger  than  cricket  balls,  and  the  smallest  about  the 
size  of  small  peas. 

More  than  a  thousand  years  before  the  birth  of 
Christ  a  great  Phoenician  philosopher  believed 
that  all  matter  —  solids,  liquids,  and  gases  —  was 
built  up  from  infinitely  small  aggregations  of  atoms. 
The  learned  men  of  Greece  enlarged  upon  his  views 
but  this  philosophy  passed  into  oblivion  with  the 
destruction  of  Rome  and  the  coming  of  the  Dark 
Ages,  and  it  was  not  revived  until  about  one  hundred 
and  fifty  years  ago.  The  ancients  could  not  prove 
their  theory,  while  we  to-day  can  count  the  atoms 
and  determine  their  size  and  motions ;  and,  exceed- 
ingly small  though  they  be,  we  no  longer  believe 


EARTH'S  FOUR  ATMOSPHERES        31 

them  to  be  indivisible  in  structure.  On  the  contrary, 
we  know  that  each  atom  consists  of  particles  of  posi- 
tive and  negative  electricity.  The  negative  elec- 
trons arrange  themselves  about  a  positive  electron 
for  a  nucleus  and,  rotating  about  it  as  if  it  were  a  cen- 
tral sun  with  planets,  constitute  an  atom.  All  mat- 
ter reduced  to  the  ultimate  electron  is  precisely  alike. 
The  difference  in  matter  is  determined  by  the  num- 
ber of  negative  electrons  that  are  attracted  and  held 
in  place  by  the  positive  nucleus  that  is  at  the  center 
of  each  atom  of  which  a  particular  kind  of  matter 
is  composed.  Each  of  the  ninety-two  elements 
which  we  believe  constitute  the  ninety-two  different 
forms  of  simple  matter  has  an  atom  with  its  own 
peculiar  type  of  nucleus,  which  nucleus  differs  from 
those  of  the  others  only  in  the  amount  of  positive 
electricity  it  contains.  Thus  hydrogen,  the  light- 
est of  all  gases,  whose  weight  is  taken  as  unity  in 
measuring  the  magnitude  of  other  gases,  has  a 
nucleus  whose  positive  charge  of  electricity  is  only 
sufficient  to  attract  one  negative  electron.  The 
next  element,  helium,  has  a  nucleus  with  a  double 
positive  charge  and  consequently  holds  two  electrons 
or  planets  to  pay  it  homage.  In  like  manner  the 
carbon  atom  contains  six  electrons ;  oxygen,  eight ; 
aluminum,  thirteen ;  nitrogen,  fourteen ;  sulphur, 


32  THE  NEW  AIR  WORLD 

sixteen;  iron,  twenty-six;  copper,  twenty -nine;  sil- 
ver, forty-seven;  gold,  seventy-nine;  mercury, 
eighty ;  lead,  eighty-two ;  bismuth,  eighty -three ; 
radium,  eighty-eight ;  thorium,  ninety ;  and  uranium, 
ninety-two.  The  chemical  union  of  these  elementary 
forms  of  matter  creates  other  forms.  For  instance, 
the  union  of  two  atoms  of  hydrogen  and  one  of  oxygen 
constitutes  a  molecule  of  water.  But  the  gases  of 
the  atmosphere  are  not  in  chemical  union ;  they  exist 
in  the  form  of  a  mechanical  mixture,  each  acting  as 
though  the  others  were  not  present. 

It  is  important  that  this  mixture  of  gases  that 
constitutes  our  air  be  maintained  in  the  right  pro- 
portion. Only  a  slight  difference  in  relative  amounts 
might  be  disastrous  to  life.  An  increase  in  the 
oxygen  would  stimulate  mental  and  physical  activ- 
ities and  hold  the  human  faculties  at  a  higher  tension. 
Man  would  accomplish  more  in  a  given  time,  but 
his  span  of  life  would  be  shortened ;  and  too  great 
an  increase  in  the  proportion  of  this  stimulating 
element  would  quickly  terminate  life.  Conversely 
an  increase  in  the  nitrogen  would  render  all  life 
more  lethargic  and  man  would  be  slower  to  act  and 
to  think;  and  too  great  an  increase  would  smother 
every  living  thing. 

In  addition  to  the  gases  named,  the  air  contains 


EARTH'S  FOUR  ATMOSPHERES        33 


small  amounts  of  many  other  substances,  —  argon, 
nitric  acid,  ammonia,  ozone,  xenon,  krypton,  and 
neon;  as  well  as  organic  matter,  germs,  and  dust 
in  suspension.  Over  the  land  it  contains  sulphates 
in  minute  quantities,  and  over  the  sea  and  near 
the  seashore  salt  left  from  the  evaporated  spray. 
The  proportion  of  each  component  of  the  atmos- 
phere by  volume  of  the  total  atmosphere  is  different 
from  its  proportion  by  weight.  The  percentages  for 
the  more  abundant  gases  are  as  follows : 


BT  VOLUME 

BY  WEIGHT 

Nitroscn                 •     • 

78.04 

75.46 

20.99 

23.19 

Argon 

0.94 

1.30 

Carbon  dioxide  .     .     .     . 

0.03 

0.05 

100.00 

100.00 

Nitrogen.  Its  principal  functions  are  to  dilute 
the  oxygen  and  to  furnish  food  to  vegetation.  It 
is  inert  and  does  not  manifest  many  marked  chemi- 
cal affinities.  Its  lack  of  activity  is  shown  by  the 
fact  that  it  will  neither  support  combustion  nor 
burn. 

Oxygen.  Oxygen,  unlike  nitrogen,  is  an  active 
element  that  readily  enters  into  chemical  combina- 
tion with  many  other  elements,  and  it  is  second  in 
quantity  to  nitrogen.  With  hydrogen  it  con- 


34  THE  NEW  AIR  WORLD 

stitutes  eight  ninths,  by  weight,  of  water ;  combined 
with  other  elements  it  constitutes  forty  to  fifty  per 
cent,  of  the  crust  of  the  earth.  It  burns  so  readily 
that  were  it  not  greatly  diluted  by  an  inert  gas 
like  nitrogen  it  would  be  difficult  if  not  impossible 
to  stop  a  conflagration  when  once  started.  It  is 
the  vitalizing  principle  in  all  forms  of  life.  By  its 
chemical  union  with  carbon  in  the  tissues  of  plants 
and  animals  it  develops  the  energy  manifested  in 
their  movements. 

In  the  free  air  up  to  about  seven  miles  high  there 
is  no  variation  in  the  proportion  of  oxygen.  But 
variations  of  marked  importance  to  health  and  life 
occur  in  places  where  ventilation  is  restricted,  and 
especially  where  living  creatures  exist  in  closed 
rooms,  and  where  combustion  occurs  in  confined 
places.  The  following  variations  in  percentages  by 
volume  were  found  hi  careful  analyses  by  Robert 
Angus  Smith :  On  the  seashore  of  Scotland,  20.99 ; 
open  places  in  London,  20.95 ;  in  a  small  room  where 
a  petroleum  lamp  had  been  burning  six  hours,  20.83 ; 
pit  of  a  theater  at  11:30  P.M.,  20.74;  in  a  court 
room,  20.65;  in  mine  pits,  20.14.  He  took  samples 
from  one  mine  that  showed  18.27,  the  candles  going 
out  when  the  amount  had  decreased  to  18.50. 

The  absorption  of  oxygen  by  putrid  matter  and 


EARTH'S  FOUR  ATMOSPHERES        35 

by  living  beings  in  the  process  of  breathing,  and  the 
giving  out  of  carbon  dioxide  by  both  explain  the 
deficiency  of  oxygen  that  is  found  over  large  cities, 
which  is  more  marked  when  the  air  is  moving  but 
little  and  where  the  city  is  located  in  a  depression  or 
near  swampy  lands. 

Both  animals  and  plants  inhale  oxygen  and  ex- 
hale carbon  dioxide  with  the  unchanged  nitrogen. 
The  process  automatically  proceeds  both  night  and 
day.  It  should  not  be  confused  with  the  opposite 
action  of  plants  under  the  influence  of  sunlight  in 
taking  in  and  decomposing  carbon  dioxide  and  expel- 
ling pure  oxygen. 

Carbon  Dioxide.  It  forms  the  chief  food  supply 
of  all  green-leaved  plants.  It  is  as  necessary  to  the 
life  of  vegetation  as  is  oxygen  in  the  supporting  of 
animal  life.  In  the  ratio  of  seventy-seven  to  one 
hundred  there  is  less  of  this  gas  present  in  the  at- 
mosphere in  the  winter  than  in  the  summer;  there 
also  is  a  diurnal  maximum  and  minimum.  In  the 
open  country  the  amount  averages  about  0.035  per 
cent,  by  volume.  In  cities  the  amount  is  consider- 
ably greater,  frequently  rising  to  0.07,  and  at  times 
to  0.10  when  the  wind  velocity  is  too  low  to  scatter 
the  excess  amount  that  accumulates  near  the  ground. 
Any  quantity  in  excess  of  0.06  per  cent.,  especially 


36  THE  NEW  AIR  WORLD 

if  combined  with  the  organic  matter  exhaled  from 
the  lungs  and  from  the  pores  of  the  skin  by  animals 
and  man,  is  injurious  to  health.  Angus  Smith 
found  as  much  as  0.32  per  cent,  in  crowded  theaters, 
and  2.50  in  mines.  The  latter  amount  soon  would 
destroy  animal  life. 

Vegetation,  in  addition  to  the  inhalation  of  oxygen 
and  the  expiration  of  carbon  dioxide  at  all  hours, 
absorbs  the  latter  during  the  day,  and  under  the 
influence  of  sunlight  the  green  granular  matter  that 
constitutes  the  chlorophyll  of  the  cells  of  the  leaves 
decomposes  it,  the  plant  retaining  the  carbon  and 
giving  out  the  oxygen.  Because  of  the  absence  of 
sunshine  the  chemical  activities  of  the  plant  are 
altered  at  night  and  the  absorption  of  carbon  dioxide 
ceases;  therefore  over  the  land  the  maximum 
amount  occurs  during  the  nighttime.  This  gas  is 
dissolved  in  seawater  and  given  off  with  a  rise  in 
temperature,  which  causes  the  maximum  amount 
over  oceans  to  occur  at  midday. 

Carbon  dioxide  is  1.50  times  as  dense  as  an  equal 
volume  of  atmospheric  air.  Its  greater  density 
causes  it  to  collect  in  mines,  sewers,  cellars,  and 
other  low  places,  unless  there  is  forceful  ventilation. 

The  American  cold  wave  should  be  welcomed  as 
the  mighty  scavenger  of  the  air.  Its  high  velocity 


EARTH'S  FOUR  ATMOSPHERES        37 

and  great  density  cause  it  to  search  into  cracks, 
crevices,  sewers,  and  cellars  and  expel  foul  accumula- 
tions. How  sweet  and  clean  the  air  smells  and  how 
vigorous  physically  and  buoyant  mentally  one  feels 
after  a  rain  and  high  winds  !  All  nature  smiles  and 
every  form  of  life  adds  its  paean  of  joy.  Rain  washes 
out  the  carbonic  acid  gas  (carbon  dioxide)  from  the 
air,  with  dust  and  other  particles  in  suspension; 
and  the  cold  wave  enters  our  places  of  habitation 
and  drives  out  the  thieving  accumulations  of  poison- 
ous gases  that  would  rob  us  of  health  and  maintain 
conditions  of  morbidity. 

It  cannot  be  too  forcefully  stated  that  oxygen,  the 
life-sustaining  principle  of  the  air,  decreases,  and 
carbon  dioxide,  .a  poison,  increases  in  air  that  is 
breathed,  or  in  air  in  which  lamps  or  gas  jets  are 
burning ;  and  that  all  places  of  habitation,  especially 
sleeping  rooms,  should  have  a  continuous  supply  of 
fresh  air. 

Water  Vapor.  It  is  only  a  little  over  one  half  as 
dense  as  atmospheric  ah*.  In  the  arid  regions  of 
the  west  it  may  form  only  a  fraction  of  one  per  cent, 
of  the  air  by  weight ;  while  in  the  humid  regions  in 
the  eastern  part  of  the  United  States  it  may  con- 
stitute as  much  as  five  per  cent.  The  temperature 
being  the  same,  the  same  amount  is  required  to 


38  THE  NEW  AIR  WORLD 

saturate  a  given  space,  whether  it  be  a  vacuum  or 
whether  it  be  filled  with  air.  Air  doubles  its  ca- 
pacity for  water  vapor  with  each  increase  of  eighteen 
to  twenty  degrees.  On  a  hot  day  in  summer,  near 
large  bodies  of  water,  it  may  constitute  as  much  as 
one  twentieth  by  weight  of  the  lower  air,  while  on 
a  cold  day  in  winter  it  may  form  no  more  than  one 
thousandth  part.  When  the  air  contains  all  the 
water  vapor  it  can  hold,  it  is  said  to  be  saturated ; 
no  more  can  be  added  to  it  until  its  temperature  is 
raised,  and  but  a  slight  lowering  of  its  temperature 
will  precipitate  a  part  of  its  water  vapor  in  the  form 
of  dew,  frost,  rain,  hail,  or  snow.  This  is  the  reason 
it  is  usually  called  water  vapor  instead  of  a  gas. 
Under  the  influence  of  heat  that  is  below  the  freezing 
point,  ice  and  snow  may  be  changed  from  the  solid 
to  the  gaseous  form,  and  water  vapor  may  be  pre- 
cipitated as  frost  or  snow  without  passing  through 
the  liquid  state. 

The  Dew  Point  is  the  temperature  of  saturation, 
—  the  temperature  to  which  a  body  of  air  must  be 
reduced  before  condensation  can  occur  and  some  of 
its  water  vapor  return  to  the  liquid  or  solid  state. 

The  Relative  Humidity  is  expressed  in  percentages 
of  the  amount  necessary  to  saturate.  At  a  tempera- 
ture of  32°  air  may  continue  to  increase  its  vapor  of 


EARTH'S  FOUR  ATMOSPHERES        39 

water  until  it  contains  2.11  grains  per  cubic  foot,  when 
it  will  be  saturated  and  its  relative  humidity  be 
one  hundred  per  cent.  If  this  same  air  be  suddenly 
raised  in  temperature  to  51°  its  capacity  per  cubic 
foot  will  be  increased  to  twice  what  it  was  at  32°, 
the  2.11  grains  will  be  equal  to  only  one  half  the 
number  necessary  to  saturate,  and  the  relative 
humidity  be  expressed  by  fifty  per  cent,  instead  of 
one  hundred  per  cent.  In  this  way  does  the  ca- 
pacity of  air  for  water  vapor  increase.  Thus  it  is 
seen  that  the  relative  humidity  of  the  air  may  in- 
crease during  the  cooling  of  nighttime  without  the 
addition  of  any  vapor  of  water,  and,  in  fact,  with  a 
decrease.  The  increase  of  relative  humidity  after 
nightfall  is  greater  in  the  country  than  in  the  city, 
where  the  presence  of  pavements  and  brick  build- 
ings retards  the  loss  of  heat. 

The  Absolute  Humidity  is  expressed  in  grains  the 
cubic  foot.  The  hygrometer  is  employed  to  measure 
the  amount  of  water  vapor. 

Hydrogen  is  the  lightest  of  all  known  gases.  Its 
density  in  comparison  with  ordinary  air  is  only 
.0692.  It  is  combustible,  and  when  five  volumes  of 
atmospheric  air  are  mixed  with  two  volumes  of 
hydrogen  the  mixture  explodes  when  ignited.  It  is 
supplied  to  the  air  by  active  volcanoes  and  in  other 


40  THE  NEW  AIU  WORLD 

ways,  but  the  speed  of  its  molecules  is  such  that  it 
readily  escapes  from  the  earth's  attraction  and 
passes  outward  into  space. 

Ozone  (Greek,  ozo,  I  smell)  is  highly  electrified 
oxygen,  in  which  the  molecules  are  broken  up  and 
reformed  so  as  to  contain  additional  atoms.  It 
is  formed  by  the  disruptive  discharge  of  light- 
ning and  by  the  great  amount  of  electricity  pres- 
ent in  the  high  levels  of  the  atmosphere,  and 
possibly  in  minute  quantities  by  the  evaporation 
of  fog  and  water  near  the  earth.  It  is  always  found 
in  the  presence  of  waterfalls  and  spraying  fountains. 
It  is  a  powerful  sanitary  agent,  readily  entering  into 
union  with  decaying  matter.  This  fact  accounts 
for  the  total  absence  of  ozone  from  the  air  of  large 
cities. 

Ozone,  in  the  minute  quantities  found  in  nature, 
is  healthful,  but  when  breathed  in  a  condensed 
form  it  has  a  highly  irritating  effect  on  the  mucous 
surfaces  of  the  respiratory  passages,  and  the  quantity 
is  not  large  that  will  cause  death.  The  healthfulness 
of  mountain  air  may  be  due  largely  to  the  increase 
with  elevation  in  the  quantity  of  ozone  and  elec- 
tricity in  the  air,  as  well  as  to  the  less  number  of 
disease  germs  and  dust  motes.  The  invigorating 
effects  of  the  crisp  air  of  the  frosty  morning  and  of 


EARTH'S  FOUR  ATMOSPHERES        41 

the  cold  wave  in  winter  may  be  increased  by  the 
activities  of  ozone. 

Ozone  has  two  daily  maxima,  the  principal  one 
occurring  between  4  and  9  A.M.  The  minima 
occur  between  10  A.M.  and  1  P.M.,  and  between 
10  P.M.  and  midnight.  The  winter  furnishes  an 
amount  greatly  in  excess  of  the  summer,  due  not 
only  to  the  less  amount  of  decaying  matter  to  take 
up  the  ozone  in  winter,  but  to  the  higher  and  more 
persistent  winds  mixing  the  lower  and  upper  air. 
The  amount  is  greater  over  the  sea  than  over  the 
land,  probably  due  to  the  absence  of  oxidizable  mat- 
ter, which  allows  the  ozone  to  accumulate  over  the 
water.  It  is  more  abundant  with  westerly  than 
with  easterly  winds,  due  to  the  fact  that  westerly 
winds  have  a  downward  component  of  motion ;  but 
if  the  westerly  winds  be  weak  and  the  easterly  winds 
come  from  over  a  large  body  of  water  the  conditions 
may  be  reversed. 

Microbes  of  the  Air.  The  air  transports  vast  armies 
of  unseen  workers.  Some  are  enemies;  others  are 
benefactors  of  the  human  family.  The  useful 
varieties  are  energetic  in  clearing  away  the  refuse  of 
animal  and  vegetable  life,  in  fixing  fertilizing  gases 
in  the  soil,  in  giving  flavor  to  fruits  and  proper 
growth  to  leguminous  crops,  in  transforming  the 


42  THE  NEW  AIR  WORLD 

crudest  must  into  the  best  claret,  and  the  poorest 
tobacco  leaf  into  the  fragrant  Havana;  in  curing 
cheese  and  butter  and  fermenting  beer,  and  in  a 
multitude  of  other  useful  employments.  The  malev- 
olent varieties,  if  they  gain  lodgment  in  suitable 
human  tissues  before  sunlight  weakens  their  virility, 
disseminate  certain  forms  of  disease. 

In  picking  a  permanent  place  of  abode,  remember 
that  there  are  many  less  disease  microbes  in  the  air 
of  the  open  country  than  in  that  of  the  city,  and 
that  few  are  found  in  the  air  of  mountains,  or  in 
that  of  the  ocean.  The  average  number  of  bacteria 
in  a  cubic  meter  of  air  in  the  city  of  Paris  has  been 
found  to  be  4790,  while  ten  miles  away  in  the  country 
the  number  was  only  345. 

Accurate  analyses  of  the  air  of  crowded  tenements 
always  have  shown  large  numbers  of  bacteria,  but 
the  number  was  found  to  be  small  in  well-ventilated 
city  houses  that  let  in  an  abundance  of  sunshine  to 
their  interiors.  It  is  better  to  have  color  in  the 
cheeks  of  the  occupants  than  in  the  furnishings  of 
a  house.  Curtains  and  heavy  drapery  not  only 
furnish  a  refuge  for  the  microbes  of  disease,  but  they 
may  be  so  hung  as  to  exclude  the  purifying  sunshine. 
The  amount  of  sunshine  is  nearly  as  important  as 
the  quantity  of  air,  for  most  of  the  microbes  of 


EARTH'S  FOUR  ATMOSPHERES        43 

disease  quickly  die,  or  are  rendered  less  virulent, 
under  its  influence. 

Bacteria  exist  in  small  numbers,  if  at  all,  at  alti- 
tudes where  snow  forms,  but  snow  gathers  them  as 
it  falls  through  the  lower  air.  Ice  contains  bacteria, 
but  not  in  any  such  quantity  as  the  water  from  which 
it  freezes.  Ice  forms  in  the  open  at  the  surface  of 
the  water,  or  about  numerous  small  particles  of  matter 
in  suspension,  which  rise  at  once  to  the  top  as  soon  as 
the  ice  congeals  about  them  in  the  form  of  a  buoyant 
covering ;  meanwhile  sediment  is  continually  settling 
to  the  bottom,  carrying  bacteria  with  it.  Ice  forms 
more  readily  in  quiet  water,  where  sedimentation 
has  been  most  rapid,  and  where,  therefore,  there  are 
the  fewest  bacteria  in  position  to  be  included.  More 
disease  germs  exist  in  river  water  in  winter  than  in 
summer,  which  may  be  due  to  the  greater  disin- 
fecting power  of  the  sun's  rays  during  summer. 

Dust  Motes  of  the  Air.  As  the  earth  pursues  its 
course  about  the  sun,  dust  rains  into  its  atmosphere 
from  outer  space.  Meteors  that  are  burned 
through  the  heat  generated  by  striking  into  our  air 
contribute  to  the  supply,  as  do  volcanoes,  com- 
bustion, spray  from  the  ocean,  and  matter  lifted 
up  by  the  action  of  the  wind. 

Dust  from  the  eruption  of  Krakatoa  was  wafted 


44  THE  NEW  AIR  WORLD 

entirely  around  the  earth,  falling  upon  the  decks  of 
ships  in  all  the  seas  of  the  world.  It  affected  the 
colors  of  the  sky  for  two  or  three  years  after  the 
explosion. 

As  in  the  case  of  microbes,  the  number  of  dust 
particles  is  far  greater  in  cities  than  in  the  country, 
being  least  on  high  mountain  tops  and  over  the 
oceans.  The  air  in  large  cities  invariably  shows 
hundreds  of  thousands  of  dust  motes  to  the  cubic 
centimeter,  that  of  the  village  thousands,  and  that 
of  the  open  country  some  hundreds.  Dust-free  air 
is  also  germ-free.  Many  experiments  have  shown 
that  air  freed  of  dust  motes  has  at  the  same  time 
been  cleared  of  the  microorganisms  that  cause 
disease,  putrefaction,  and  fermentation;  and  that 
germ-free  flesh  or  liquids  may  be  indefinitely  ex- 
posed in  such  air  without  fermentation  or  decay. 

How  Dust  Motes  Are  Counted.  Many  of  the 
particles  are  too  small  to  be  seen  by  the  highest 
powers  of  the  microscope,  yet  Aitken,  by  a  most 
ingenious  method  of  making  them  centers  of  con- 
densation —  that  is,  making  them  the  nuclei  of  small 
raindrops  —  was  able  to  count  the  number  in  a  given 
volume  of  air.  When  ordinary  air  is  saturated  and 
then  cooled  the  cloud  formed  is  so  dense  that  it  is 
impossible  to  count  the  tiny  droplets  that  form  the 


EARTH'S  FOUR  ATMOSPHERES        45 

cloud.  But  we  can  make  the  number  of  dust  par- 
ticles (and  therefore  the  number  of  visible  points  of 
condensation)  in  a  given  volume  of  air  as  small  as 
we  wish  by  mixing  a  little  dusty  air  with  a  large 
amount  of  dustless  air,  and  we  can  allow  the  par- 
ticles to  fall  on  a  bright  surface  and  can  count  them 
by  means  of  a  lens  or  microscope.  By  simply  al- 
lowing for  the  proportion  of  the  dustless  to  the  dusty 
air,  and  making  a  corresponding  allowance  for  the 
dilution,  we  calculate  the  number  of  particles. 

Dust  Motes  and  Illumination  of  the  Atmosphere. 
One  of  the  most  important  functions  of  dust  motes 
is  the  diffusion  or  scattering  of  sunlight.  What  a 
different  world  this  would  be  without  these  tiny 
inanimate  friends  of  man !  If  there  were  no  dust  in 
suspension  in  the  air,  nothing  would  be  visible  ex- 
cept what  received  direct  light,  or  light  reflected 
from  some  illuminated  surface,  and  the  air  occupy- 
ing space  between  illuminated  objects  would  be 
practically  dark.  If  the  observer  be  in  a  room  with 
a  powerful  electric  light  he  would  see  the  walls 
and  the  objects  in  the  room,  but  if  the  air  were  free 
of  dust  motes,  he  would  find  that  the  space  between 
him  and  the  walls  and  between  the  various  objects 
would  be  as  inky  black  as  is  the  space  between  the 
twinkling  stars  on  a  clear  night. 


46 


THE  NEW  AIR  WORLD 


Figure  2  is  a  cubical  box,  with  a  glass  front.     If  a 
glutinous  substance  be  spread  over  the  bottom  and 

— ^  the  box  allowed 

to  remain  quies- 
cent for  from 
lc  five  to  seven 
days  the  dust 
motes  will 
slowly  settle 
down  and  at- 
tach them- 
selves to  the 
bottom.  The 
air  then  will  be 
what  is  called 

FIG.  2.  —  Showing  light  from  lamp  a  passing  into 

dust-free  air  at  b,  and  passing  out  at  c  without    "optically 
illuminating  the  interior.  ,,      XT 

pure.       Now, 

if  it  be  taken  into  a  dark  room  and  an  inclosed  lamp  at 
a  be  allowed  to  send  a  beam  of  light  into  the  window 
at  b  and  out  at  c,  it  will  be  found  that  the  interior 
remains  dark  no  matter  how  powerful  the  light  from 
the  lamp.  The  light  is  seen  to  enter  and  to  leave 
but  where  it  encounters  the  dust-free  air  there  is 
nothing  to  scatter  the  light  rays  and  they  remain 
invisible  to  the  eye. 
Pust  Motes  Prolong  Twilight.  The  bending  or 


EARTH'S  FOUR  ATMOSPHERES        47 

refraction  of  light  as  the  sun's  rays  pass  obliquely 
through  the  air  at  sunrise  and  at  sunset  displaces 
the  apparent  position  of  the  sun,  elevating  it  by  an 
amount  about  equal  to  its  own  apparent  diameter, 
so  that  one  may  see  it  and  receive  its  light  when 
geometrically  it  is  entirely  below  the  horizon.  A 
little  later  in  the  evening  and  its  rays  fall  upon  the 
upper  air  too  obliquely  to  be  bent  down  to  the  earth 
by  refraction ;  but  darkness  does  not  yet  ensue,  for 
the  rays  are  scattered  by  the  dust  motes  and  pos- 
sibly by  the  molecules  of  the  gases  and  sent  down- 
ward from  particle  to  particle,  resulting  in  a  soft 
shimmering  light  that  almost  imperceptibly  fades 
away,  and  which  in  higher  latitudes  may  last  for 
hours. 


CHAPTER  V 
LIGHT,  HEAT,  AND  TEMPERATURE 

MORE  WONDERFUL  THAN  ANY  FICTION  ARE  THE  FACT 
OP  INVISIBLE  LIGHT,  AND  THE  DIFFERENCE  BE- 
TWEEN HEAT  AND  TEMPERATURE 

THE  heat  that  escapes  from  the  earth's  interior 
is  minute  in  comparison  to  that  received  from  the 
sun,  which  is  the  main  source  of  the  earth's  supply. 
Heat  is  manifested  by  the  motions  of  the  molecules 
of  matter,  whether  solid,  liquid,  or  gaseous.  It  is 
transmitted  through  space  in  some  mysterious  man- 
ner, for  space  is  practically  void  of  an  atmosphere. 
One  cannot  conceive  of  motion  taking  place  hi  a 
void,  for  there  is  nothing  to  move.  Therefore  it  is 
assumed  that  interstellar  space  must  be  filled  with 
a  transmitting  medium;  to  this  the  name  of  ether 
has  been  given.  Nothing  is  known  of  its  structure, 
but  it  is  believed  that  it  penetrates  all  bodies  and 
fills  the  space  between  their  molecules. 


LIGHT,  HEAT,  TEMPERATURE        49 

How  Heat  and  Light  Reach  the  Earth.  The  heat 
of  the  sun  is  some  forty-six  thousand  times  as  intense 
as  is  the  heat  of  the  earth.  The  violent  agitations 
of  the  molecules  of  the  sun's  hot  atmosphere  impart 
vibrations  to  the  ether  of  space,  which  decrease  in 
effectiveness  inversely  as  the  square  of  the  distance ; 
that  is  to  say,  that  if  the  earth  were  twice  as  far  from 
the  sun  as  it  is,  the  intensity  of  the  solar  rays  would 
be  one  fourth  of  what  they  are  now.  These  vibra- 
tions are  called  solar  energy.  They  pass  through 
space  without  perceptibly  warming  or  lighting  it. 
When  they  encounter  the  molecules  of  the  earth's 
atmosphere,  and  the  dust  and  cloud  in  suspension 
in  the  air,  or  impinge  upon  the  solid  matter  of  the 
earth,  they  are  transmuted  back  into  molecular 
agitations,  and  manifest  themselves  in  a  multitude 
of  forms,  such  as  heat,  light,  chemical  rays,  elec- 
tricity, etc. 

The  Difference  between  Heat  and  Temperature. 
The  agitation  of  the  molecules  of  a  substance  set  up 
by  the  absorption  of  heat  is  indicated  by  temperature, 
which  gives  no  measure  of  the  quantity  of  heat  ab- 
sorbed, the  quantity  varying  widely  for  different 
kinds  of  matter.  The  amount  of  heat  necessary  to 
raise  one  pound  of  water  1°  F.  is  the  heat  unit  gen- 
erally employed  in  commerce;  but  in  scientific 


50  THE  NEW  AIR  WORLD 

research  the  amount  necessary  to  raise  one  gram 
of  water  1°  Centigrade  is  the  unit  of  heat  best  adapted 
to  use.  It  is  called  the  gram-calorie. 

Let  us  take  a  glass  filled  with  boiling  water.  You 
see  the  glass  and  the  water  because  they  reflect 
to  the  eye  light  waves  received  from  some  source, 
—  possibly  the  sunlight  that  is  diffused  by  the  dust 
motes  of  the  air  into  the  room  through  the  window. 
But  the  glass  and  the  water  radiate  other  waves  to 
which  the  eye  is  not  sensible;  these  invisible  long 
heat  waves  may  be  felt  by  the  nerves  of  the  hand. 
They  warm  all  matter  upon  which  they  fall  by  add- 
ing to  the  agitation  of  the  molecules  of  which  it  is 
composed ;  but  they  do  not  warm  all  matter  equally. 
The  waves  that  reach  dark  bodies  are  broken  up ; 
that  is  to  say,  absorbed.  Their  energy  is  trans- 
muted into  sensible  heat,  and  in  the  place  of  the 
waves  we  have  molecular  vibrations  in  the  matter, 
which  are  made  manifest  by  a  rise  in  its  temperature. 
Dark  rough  surfaces  more  completely  absorb  the 
waves  and  therefore  rise  to  a  higher  temperature 
than  the  same  surfaces  when  smooth.  When  the 
waves  encounter  bright  and  highly  polished  sur- 
faces the  effect  is  quite  different ;  then  most  of  them 
are  reflected  away  and  therefore  warm  the  matter 
but  little.  These  reflected  waves  are  not  broken 


LIGHT,  HEAT,  TEMPERATURE        51 

up,  but  on  the  contrary  start  off  in  some  new  di- 
rection, possibly  falling  upon  and  warming  some 
matter  more  receptive  to  their  influence.  The 
higher  the  polish  the  more  completely  are  the  waves 
reflected. 

Difference  between  Light  Waves,  Heat  Waves, 
and  Sound  Waves.  The  light  and  the  heat  waves 
of  the  ether  are  infinitesimal  ripples  as  compared  to 
the  backward  and  forward  pulsations  that  con- 
stitute the  sound  waves  of  the  air.  Within  a  space 
of  one  inch  there  are  sixty-six  thousand  of  the  violet 
waves  of  light,  which  are  the  shortest  etheric  vi- 
brations to  which  the  human  eye  responds,  and 
over  thirty  thousand  of  the  red  waves,  the  longest 
that  affect  the  eye;  while  the  sound  waves  of  the 
air  vary  from  about  one  foot  for  the  shrill  notes  of  the 
human  voice  to  four  feet  for  the  middle  C  of  the  piano- 
forte. A  shrill  whistle  produces  waves  of  about  one 
half  inch.  There  are  twenty -two  thousand  of  certain 
heat  waves  to  the  inch,  and  these,  like  some  of  the 
light  waves  of  the  ether,  are  invisible. 

There  is  also  a  vast  difference  between  the  velocity 
of  vibration  of  the  air  waves  and  those  of  the  ether. 
The  human  ear  is  sensitive  to  sound  waves  of  some- 
where between  twenty -nine  per  second  to  thirty -eight 
thousand  per  second ;  while  the  eye  responds  to  light 


52  THE  NEW  AIR  WORLD 

waves  of  from  five  hundred  million  to  one  billion  per 
second.  Some  ears  are  better  adjusted  to  the  low 
vibrations  and  some  to  the  high,  and  the  ears  of  no 
one  hear  any  but  a  small  part  of  the  melody  of  a  great 
symphony.  Tyndall  could  hear  the  sharp  chirp  of 
thousands  of  insects  that  were  inaudible  to  his  guide 
as  the  two  climbed  the  Alps,  but  the  guide's  ears 
responded  to  the  long,  slow  waves  that  came  from 
the  dull  tread  of  the  donkey's  hoofs  farther  up  the 
mountain,  which  waves  the  scientist  was  unable  to 
hear.  Likewise  some  eyes  are  able  to  penetrate 
far  into  the  violet,  or  the  red,  or  both,  and  some  are 
unable  to  distinguish  between  certain  colors. 

Chemical  Rays  of  Light.  The  chemical  or  photo- 
graphic rays  have  still  shorter  waves  than  the  vio- 
let. They  produce  special  physiological  effects  in 
vegetable  and  animal  tissues,  and,  acting  upon 
particular  kinds  of  matter,  they  cause  fluorescence, 
which  is  the  property  possessed  by  some  bodies  of 
giving  off,  when  illuminated,  light  of  a  color  different 
from  their  own  and  from  that  of  the  light  that 
illuminates  them.  These  chemical  rays  are  some- 
times called  ultra-violet  rays. 

Invisible  Light.  From  a  reading  of  the  immedi- 
ately preceding  paragraphs  one  may  be  prepared 
for  the  startling  statement  that  there  is  such  a  thing 


LIGHT,  HEAT,  TEMPERATURE        53 

as  invisible  light.  Vibrations  of  the  ether  that 
move  slower  than  those  that  give  to  the  eye  the 
sensation  of  red  are  invisible,  as  are  those  that  move 
faster  than  the  violet  rays,  and  it  is  certain  that 
neither  the  eye  of  man  nor  of  animal  ever  will  see 
but  a  small  part  of  the  beauty  of  a  landscape  or  the 
delicate  coloring  of  a  flower.  The  eye  only  takes  in 
and  renders  sensible  to  the  brain  the  red,  orange, 
yellow,  green,  blue,  indigo,  violet,  and  their  various 
tints,  but  the  delicate  instruments  of  science  reveal 
many  other  colors.  One  sees  as  through  a  glass 
darkly,  for  the  gentle  signals  that  might  reveal  the 
beauties  of  Paradise  fall  upon  the  eye  unheeded. 
A  keener  vision  and  a  more  complete  appreciation 
of  the  beauties  and  the  wonders  of  the  universe  await 
one  on  the  other  side  of  the  gauzy  veil  of  immortal- 
ity. The  finger  tips  of  the  outstretched  arms  may 
span  the  river  of  life  and  the  ethereal  breath  of 
loved  ones  may  be  caressing  one's  cheek.  The  music 
of  the  spheres  is  not  a  myth ;  the  lily  or  the  rose  as 
it  opens  its  petals  to  receive  the  benediction  of  the 
morning  sun  may  give  forth  a  veritable  paean  of 
joy.  A  rose  bush  may  be  a  grander  symphony 
than  anything  that  Beethoven  ever  wrote.  What 
to  us  is  the  invisible  light  may  be  the  illumination 
that  guides  the  sweep  of  the  angels'  wings. 


54  THE  NEW  AIR  WORLD 

How  Heat  Moves  through  or  Is  Transmitted  by 
Matter.  Heat  passes  by  contact  from  the  warmer 
to  the  colder  molecules  of  a  body.  This  action  is 
called  conduction.  When  one  end  of  a  bar  of  iron 
is  held  in  a  fire,  the  end  away  from  the  fire  soon 
becomes  too  hot  to  hold  in  the  hand,  because  heat 
is  rapidly  transferred  from  the  hot  portion  of  the 
bar  to  the  cooler  portion  by  conduction,  showing 
that  iron  is  a  good  conductor.  On  the  other  hand, 
the  end  of  a  stick  of  wood  can  be  held  in  the  fire 
until  it  is  completely  consumed  without  the  other 
end  becoming  too  warm  to  hold,  indicating  that 
wood  is  a  poor  conductor.  Metals  are  the  best 
conductors,  silver  leading  the  list,  with  copper 
second.  Snow  and  ice  and  fibrous  and  porous 
substances  are  poor  conductors,  and  are  called 
insulators.  Air  and  water  are  also  poor  conductors. 
The  fur  of  animals  and  the  feathers  of  birds  protect 
against  the  rapid  loss  of  heat  because  they  contain 
numerous  interstices  filled  with  air,  a  poor  con- 
ductor. Heat  is  lost  by  radiation  when  the  mole- 
cules of  matter  set  up  vibration  in  the  ether.  The 
atmosphere  itself  performs  this  function  on  a  large 
scale  when  the  sky  is  cloudless,  so  that  radiated 
heat  is  not  absorbed  by  the  cloud  covering  and  its 
loss  into  space  restricted.  When  air  or  water  is 


LIGHT,  HEAT,  TEMPERATURE         55 

not  evenly  or  homogeneously  heated  a  circulation 
is  set  up  in  which  the  colder  part  settles  down  and 
the  warmer  rises.  This  is  called  convection.  The 
air  that  is  heated  by  contact  with  a  stove  rises  and 
passes  along  the  ceiling  to  the  colder  parts  of  the 
room,  gradually  parting  with  its  heat  until  it  is  no 
warmer  than  the  air  next  adjacent  to  it,  and  slowly 
settling  to  the  floor  as  the  cold  air  beneath  it  moves 
toward  the  stove,  is  warmed  and  sent  aloft,  the  first 
air  finally  making  a  complete  circuit  and  returning 
to  the  stove  again.  In  this  way  the  heat  is  dis- 
tributed by  convection  throughout  the  whole  room. 
When  one  part  of  the  earth's  surface  becomes  hot- 
ter than  another  a  similar  action  takes  place  on  a 
large  scale.  The  region  of  greater  temperature 
warms  the  air  above  it,  and  the  surrounding  denser 
air  flows  in  along  the  surface,  forcing  the  lighter  air 
to  rise,  when  it  in  turn  is  similarly  warmed  and 
driven  up. 

The  clear  waters  of  lakes  and  rivers  and  of  the 
ocean  permit  the  passage  of  heat  waves  to  a  con- 
siderable depth  before  they  are  completely  absorbed. 
On  a  cold  day  in  winter,  when  the  sun  is  shining 
brightly,  a  room  with  spacious  windows  may  become 
as  warm  as  though  heated  by  a  furnace,  simply  by 
the  capacity  of  the  glass  in  the  windows  to  transmit 


56  THE  NEW  AIR  WORLD 

the  heat  waves  of  the  sun  without  considerable  ab- 
sorption, and  at  the  same  time  prevent  the  escape 
of  the  longer  heat  waves  that  are  radiated  from  the 
interior  walls  of  the  room.  This  capacity  of  mat- 
ter to  transmit  heat  waves  without  absorption  is 
called  diathermancy.  The  clear  atmosphere  is  an 
exceedingly  good  transmitter,  and  rock  salt  is  one 
of  the  best  of  all  solids. 

The  capacity  of  a  body  to  transmit  light  without 
absorbing  it  and  becoming  luminous  is  called  trans- 
parency. Air  freed  of  dust  motes  is  almost  per- 
fectly transparent.  In  this  state  it  is  said  to  be 
optically  pure.  But  the  ordinary  air  of  nature,  with 
its  moisture  and  dust,  absorbs  most  of  the  blue 
wave  lengths  and  also  many  of  the  longer  ones  of  the 
other  colors  of  the  spectrum. 

The  capacity  of  a  body  for  heat  is  called  its  specific 
heat.  With  but  few  exceptions  the  specific  heats  of 
liquids  are  much  greater  than  those  of  solids  or 
gases.  It  requires  ten  times  the  quantity  of  heat 
to  raise  a  pound  of  water  one  degree  that  it  does 
a  pound  of  iron.  Ice  has  the  greatest  specific  heat 
of  any  of  the  solids,  except  paraffin  and  wood. 

When  a  solid  is  melted  or  a  liquid  vaporized  a 
large  amount  of  heat  becomes  latent,  insensible  to 
the  touch;  it  disappears  as  heat.  This  is  one  of 


LIGHT,  HEAT,  TEMPERATURE         57 

the  most  wonderful  of  the  phenomena  of  nature. 
It  matters  not  how  long  the  time  may  be,  an  hour, 
a  day,  a  year,  or  a  thousand  years  after  the  solid  is 
melted  or  the  liquid  turned  to  vapor,  so  soon  as  the 
vapor  returns  to  the  liquid  state  or  the  liquid  to  a 
solid  condition,  the  latent  heat  becomes  sensible  in 
exactly  the  same  degree  in  which  it  previously 
existed.  Let  us  illustrate  with  a  pound  of  ice  at 
zero  F.  Sixteen  heat  units,  or  sixteen  times  as 
much  heat  as  is  required  to  raise  one  pound  of  water 
one  degree,  must  be  absorbed  by  this  pound  of  ice 
to  raise  its  temperature  to  the  melting  point  (32°) ; 
and  then  one  hundred  forty-four  more  heat  units 
must  be  absorbed  to  so  far  overcome  the  tendency 
of  the  molecules  to  adhere,  or  remain  together, 
that  the  molecules  may  roll  the  one  about  the  other 
in  the  liquid  form,  but  with  this  important  differ- 
ence: the  one  hundred  forty-four  units  become 
latent  and  do  not,  therefore,  cause  any  increase  in 
temperature,  as  the  sixteen  heat  units  did  in  raising 
the  temperature  of  the  ice.  The  large  quantity  of 
heat  required  to  change  the  ice  to  a  liquid  is  called 
the  latent  heat  of  melting.  Any  further  addition 
of  heat  after  the  melting  is  complete  causes  an 
increase  in  temperature,  and  one  hundred  eighty 
heat  units  will  raise  it  to  the  boiling  point.  Water 


58  THE  NEW  AIR  WORLD 

boils  at  212°  at  sea  level  and  normal  pressure ;  that 
is  to  say,  at  that  temperature  the  agitation  of  the 
molecules  of  water  is  so  great  as  to  overcome  both 
cohesion  and  the  weight  with  which  the  air  presses 
down  upon  them,  and  cause  them  to  fly  away  in  the 
form  of  steam,  which  is  invisible  when  confined 
inside  a  boiler.  But  the  entire  pound  of  water  is 
not  instantly  changed  to  the  gaseous  condition,  for 
with  the  sending  off  of  the  first  few  molecules  some 
heat  is  rendered  latent,  and  more  must  be  supplied 
or  the  boiling  ceases ;  in  fact  the  enormous  quantity 
of  964.62  heat  units  must  be  supplied  to  entirely 
change  the  pound  of  water  to  steam,  but  at  no  time 
does  the  temperature  rise  above  212°.  As  in  the 
former  case  of  changing  the  solid  to  a  liquid,  a  large 
amount  of  heat  becomes  latent;  in  this  case  it  is 
called  the  latent  heat  of  vaporization. 

Now  carefully  fix  in  the  mind  that  a  liquid  does 
not  need  to  be  raised  to  its  boiling  point  before 
vaporization  begins,  for  it  operates  at  all  tem- 
peratures, even  after  the  liquid  is  frozen,  but  much 
more  rapidly  from  the  liquid.  If  one  wishes  to  test 
this :  weigh  a  piece  of  ice  during  very  cold  weather. 
Then  leave  it  out  in  a  temperature  that  is  below 
freezing  for  several  days,  and  on  weighing  again  it 
will  be  found  that  the  ice  has  lost  weight.  All 


LIGHT,  HEAT,   TEMPERATURE         59 

evaporation  produces  a  cooling  effect  because  of  the 
heat  that  is  rendered  latent  in  the  process  of  chang- 
ing the  liquid  or  the  solid  to  a  gaseous  form.  The 
drier  the  air  the  greater  is  the  cooling  effected  by 
keeping  the  surface  wetted,  and  the  cooling  is  ac- 
celerated by  placing  the  wet  object  where  there  is 
a  free  circulation  of  air. 

A  wooden  water  bucket  that  has  been  soaked  for 
a  day  or  two  so  that  every  part  of  the  wood  is  satu- 
rated with  water,  will,  if  kept  closed,  keep  water 
all  day  in  the  open  field  practically  as  cool  as  when 
it  left  the  deep  well,  and  often  cooler.  Not  enough 
use  is  made  of  cooling  by  evaporation  by  those  who 
have  not  ice  in  the  summer.  Inexpensive  and 
fairly  effective  refrigerators  may  be  made,  by  any 
mechanic,  of  lattice-work  sides  covered  with  any 
thick  fabric  and  kept  moist,  which  would  keep  milk, 
butter,  fruit,  vegetables,  and  cooked  meats  in  good 
condition  if  placed  in  a  hallway  with  a  good  circu- 
lation of  air,  or  in  any  shady  place  with  good  venti- 
lation. 

Most  solids  expand  with  gain  in  temperature  and 
therefore  possess  greater  volume  in  the  liquid  form 
than  in  the  solid,  and  the  temperature  of  their 
melting  points  rises  as  they  are  subjected  to  in- 
creasing pressure.  The  law  reverses  when  applied 


60  THE  NEW  AIR  WORLD 

to  ice,  which  contracts  in  melting.  To  few  is  it 
known  that  a  skater  on  ice  really  rides  upon  water 
molecules,  for  the  sharp  edge  of  the  skate,  when 
applied  to  the  ice  under  the  weight  of  one's  body,  is 
lubricated  by  the  slight  melting  of  the  ice  in  immediate 
contact  with  the  skate,  the  molecules  of  water  re- 
turning to  the  form  of  ice  as  soon  as  the  skater 
passes  and  the  pressure  is  relieved.  The  strange 
phenomenon  may  be  witnessed  by  passing  a  wire 
through  a  block  of  ice  without  severing  it  into  two 
pieces,  by  attaching  heavy  weights  to  the  two  ends 
of  the  wire  and  suspending  it  across  the  ice,  the  ice 
slowly  melting  as  the  result  of  the  pressure  applied 
by  the  underside  of  the  wire  and  freezing  molecules 
closing  the  space  on  top  of  the  wire.  By  this  pro- 
cess do  we  account  for  the  moving  of  glaciers  down 
tortuous  valleys  as  though  they  were  liquids. 

Altitude  Measured  by  Change  in  Boiling  Point 
of  Water.  The  boiling  point  of  water  at  sea  level 
and  ordinary  air  pressure  is  212°.  If  the  pressure 
of  the  atmosphere  were  increased  to  about  thirty 
pounds,  instead  of  about  fifteen  to  the  square  inch 
it  would  be  necessary  to  raise  water  to  250°  before 
boiling  would  begin.  The  changes  of  air  pressure 
due  to  the  passage  of  the  severe  storms  of  winter 
may  cause  the  boiling  point  of  water  to  vary  from 


LIGHT,   HEAT,  TEMPERATURE         61 

207°  to  215°.  This  knowledge  may  be  useful  in 
measuring  the  heights  of  mountains,  although  the 
method  does  not  give  close  results.  The  decrease 
of  pressure  with  altitude  lowers  the  boiling  point, 
the  amount  being  approximately  one  degree  for 
each  555  feet  of  ascent.  The  best  results  may  be 
secured  by  having  a  person  at  the  base  of  the  moun- 
tain, where  the  elevation  above  sea  level  is  known, 
determine  the  boiling  point  at  the  same  time  that  a 
person  on  the  mountain  top  does.  The  thermom- 
eters should  be  read  closely  to  the  fraction  of  a 
degree. 

With  the  barometer  at  its  normal  height  of  thirty 
inches,  air  at  60°  will  instantly  rise  to  the  phenomenal 
temperature  of  175.50  if  it  be  confined  and  its  pres- 
sure doubled,  and  it  will  diminish  to  one  half  of  its 
former  volume.  But  if  its  pressure  be  diminished 
one  half,  its  volume  will  expand  to  double  its  original 
size  and  its  temperature  will  fall  from  60°  to  2.4°. 
From  these  facts  the  reader  would  naturally  expect 
to  find  low  pressure  of  the  atmosphere  accompany- 
ing cold  waves  and  high  pressure  to  be  coincident 
with  warm  conditions,  which  is  exactly  the  reverse 
of  what  actually  occurs  in  the  free  air  of  nature. 
This  apparent  contradiction  will  be  made  plain  in 
the  treatment  of  cold  waves,  page  124. 


62  THE  NEW  AIR  WORLD 

A  temperature  of  459°  on  the  Fahrenheit  scale 
and  273.1°  on  the  Centigrade  represents  what  is 
called  absolute  zero.  It  is  supposed  to  be  the  tem- 
perature at  which  there  is  no  motion  of  the  mole- 
cules of  matter.  Bodies  or  planets  without  atmos- 
pheres have  temperatures  approaching  absolute 
zero,  for  there  is  no  protecting  envelope  to  absorb 
heat  or  to  prevent  the  instant  radiation  into  space 
of  that  which  impinges  upon  the  body.  Our  moon 
is  an  illustration,  and  notwithstanding  the  fierce 
beating  upon  its  surface  of  the  solar  energy  it  re- 
mains incased  in  the  intense  cold  of  space. 

The  thermometer  is  the  instrument  that  meas- 
ures temperature.  It  was  not  until  eighty-seven 
years  after  Columbus  discovered  America  that 
Galileo  discovered  the  principle  of  the  thermometer. 
This  first  instrument  was  crude.  It  consisted  of  a 
glass  bulb,  containing  air,  terminating  below  in  a 
long  glass  tube,  which  dipped  into  a  vessel  contain- 
ing colored  water.  When  the  temperature  fell  the 
contraction  of  the  air  in  the  bulb  caused  the  water 
to  rise  in  the  tube,  and  when  the  temperature  rose 
the  expansion  of  the  air  forced  the  water  to  a  lower 
level.  Galileo  also  invented  the  alcohol  thermom- 
eter in  1611,  but  the  determination  of  the  zero 
and  some  fixed  point  above  it,  by  which  to  graduate 


LIGHT,   HEAT,   TEMPERATURE         63 

the  scale,  took  years  to  evolve.  The  modern  alcohol 
and  mercury  thermometers  consist  of  a  bulb  filled 
with  the  liquid,  and  a  tube  partly  filled,  the  upper 
part  being  a  tolerably  complete  vacuum,  allowing 
the  liquid  freedom  of  movement  up  and  down  the 
tube.  When  a  tube  is  broken  one  is  surprised  to  see 
that  the  diameter  of  the  bore  is  less  than  that  of  the 
smallest  fuzzy  hair  from  the  back  of  the  hand.  The 
size  of  the  column  of  mercury  is  magnified  by  the 
action  of  light  passing  through  the  glass  of  the  tube. 

Temperatures  are  usually  taken  in  the  shade. 
The  instrument  should  be  free  from  all  bodies  that 
could  conduct  heat  to  it,  and  it  should  have  free 
circulation  of  air  about  it. 

In  a  complete  meteorological  station  automati- 
cally recording  instruments,  too  complicated  for  the 
use  of  the  layman,  record  for  each  moment  of  time 
the  temperature  of  the  air  and  its  pressure,  the 
periods  of  sunshine,  the  duration  and  the  amount 
of  rainfall,  and  the  direction  and  velocity  of  the  wind. 


CHAPTER  VI 

THE  ADVANTAGE  OF  TAKING  WEATHER 
OBSERVATIONS  AND  APPLYING  THEM  TO 
ONE'S  PERSONAL  NEEDS 

FORECASTS  MADE  FROM  THE  ANEROID  BAROMETER  — 
COLDS  PREVENTED  BY  MOISTENING  AIR  IN  LIVING 

ROOMS a     CRIMINAL     HANGED     AND     AN     INNOCENT 

MAN     FREED     BY     WEATHER      RECORDS 

Observations  from  Elites.  It  is  strange  that  the 
Chinese,  who  have  been  flying  kites  many  thou- 
sand years,  should  not  have  made  improvements  in 
the  primitive  construction  of  these  devices.  It 
remained  for  Wendham,  in  1866,  to  perceive  the 
advantage  of  superimposing  two  or  more  planes, 
one  above  the  other,  for  the  purpose  of  securing  a 
larger  area  of  sustaining  surface.  After  examining 
Figure  3  almost  any  one  can  build  an  efficient  kite. 
Heights  of  two  to  three  thousand  feet  may  be  reached 
by  using  cable-laid  twine  No.  24,  but  in  order  to 
gain  great  altitudes  pianoforte  wire  must  be  used. 
Soft  pine  is  the  best  and  most  available  material. 


TAKING  WEATHER  OBSERVATIONS    65 

Spruce  is  stronger,  but  more  difficult  to  secure.  The 
sticks  should  be  straight-grained.  The  cloth  may  be 
silk  or  the  stronger  and  finer  grades  of  cotton.  It 
should  be  torn,  not  cut.  The  ends  will  then  be 
true  and  square  with  the  fiber  of  the  cloth.  Kites 
are  used  not  only  to  secure  weather  observations, 
but  they  have  been  used  to  draw  sleds  in  the 
Arctic  region,  and  to  draw  wagons  and  boats.  By 
adjusting  the  points  at  which  the  pulling  cords  are 
attached  to  the  boat  an  ingenious  sailor  is  able  to 
proceed  nearly  at  right  angles  to  the  direction  of 
the  wind. 

When  it  is  known  that  a  box  kite  having  only 
sixty  square  feet  of  sustaining  surface,  flying  at  a 
considerable  height,  may  lift  a  person  of  ordinary 
size,  one  is  impressed  with  the  idea  that  vessels 
of  commerce  might  employ  kites  of  large  dimen- 
sions to  increase  the  speed  of  sailing  ships.  The 
kites  would  fly  in  a  stratum  whose  velocity  is 
not  restricted  by  friction  with  the  surface  of  the 
water. 

To  launch  a  kite:  run  out  about  one  hundred 
and  fifty  feet  of  the  cord  or  wire  while  the  kite  is 
held  by  an  assistant,  who  should  give  the  kite  a  toss 
upward  in  the  direction  in  which  it  must  go.  It 
is  important  that  it  be  cast  off  directly  in  line  with 


66  THE  NEW  AIR  WORLD 

the  wind.  If  the  wind  is  light  it  may  be  necessary 
to  run  a  short  distance  with  a  long  line  out  in  order  to 
effect  a  launching. 

Voluntary  Weather  Observers.  There  are  more 
than  three  thousand  voluntary  or  cooperating  ob- 
servers in  the  U.  S.  Weather  Bureau.  They  re- 
ceive no  compensation  other  than  the  publications 
of  the  Bureau.  They  are  required  to  read  their 
instruments  but  once  each  day,  as  maximum  and 
minimum  thermometers  record  the  highest  and  the 
lowest  temperatures  since  they  were  last  read  and 
set.  About  sunset  is  the  most  satisfactory  time  for 
making  the  readings,  since  the  thermometers  will 
then  show  both  the  extremes  for  the  past  twenty- 
four  hours.  As  a  rule  but  one  voluntary  observer 
is  accepted  for  a  county.  They  are  furnished  with- 
out charge  with  maximum  and  minimum  thermom- 
eters, instrument  shelters  and  rain  gauges,  but 
not  with  wind  vanes,  anemometers  for  recording 
direction  and  velocity  of  wind,  or  barometers.  But 
those  who  desire  to  become  expert  in  forecasting  the 
weather,  as  all  may  who  study  the  chapter  on  fore- 
casting, should  equip  themselves  with  an  aneroid 
barometer,  so  that  they  may  note  the  changes  in  the 
pressure  of  the  air. 

An  instrument  shelter  (Figure  4)  is  employed  to 


TAKING  WEATHER  OBSERVATIONS   67 


inn 

205     -= 

==—    85 

200  = 

ies    —  = 

———90 

COMPARISON  OF 

190—  -H 

THERMOMETER    SCALES 

185     -= 

^—    M 

A  little  study  of  the  accom- 

180 '       — 

HT 

panying  information  and  dia- 

17$    —  E§ 

'    80 

gram  will   enable  any   one  to 

170  —  = 

— 

form  a  clear  idea  of  the  various 

165     —  = 

=r—    73 

thermometer  scales  and  to  con- 

— • 

vert    temperatures    from    one 

100  •       ~ 

—  70 

scale  to  another. 

ISS     —  {I 

^ 

JISO  ~—  == 

3—    05 

Table  of  fixed  pointt. 

^3     145      —  = 

<D 

•  iiri  ii  r  ft           1  j    ( 

"HI 

rg  I3S  -i 

J-     130  = 
I2S      '    — 

E,    s$       fi 

IZ9             _ 

120  = 

=  50        g 

Centigrade.        o       too         too 

MH     IIS      -H 

to    no  —  —  = 

1-  48        « 

Reaumur..        o         8a           80 
Fahrenheit      32       312         180 

i?  'IJTl 
PI  00—  i 

fi  e           , 

i~  L°    & 

H 

—  —30      - 

Only  Fahrenheit  and  Centi- 
grade scales  are  in  general  use, 
and  the  accompanying  plate  is 
designed    to    enable    observers 

oo   t   "^  —  * 

to  convert  temperature   read- 

SO "•     H 

zr 

ings  from  one  scale  to  the  other 

176      -S 

Z^^"    «5 

without  resorting  to  a  mathe- 

»» ...      ==- 

3SS 

matical  formula. 

c  0   J-       —  : 

~--}0 

For  accurate  and  precise  re- 

65      «—  JEE 

— 

ductions  between  the  different 

60  = 

—  —    1$ 

scales  the  following  rules  should 

55     *_= 

be  used  : 

r  rt   == 

^2 

1.   To  convert  Fahrenheit  to 

50  T1-  '     —  : 

1  10 

Centigrade:    Subtract  32  and 

40    '        === 

=l—    5 

multiply  by  five  ninths. 
2.    To  convert  Centigrade  to 

= 

Mcliin^lce    32  -,!  "^ 

^—  0 

Fahrenheit  :   Multiply  by  nine 
fifths  and  add  32. 
3.   To  convert  Fahrenheit  to 

55     _=! 

Reaumur:     Subtract    32    and 

20  S 
1  5        — 



multiply  by  four  ninths. 
4.   To  convert  Reaumur  to 

IX.                     == 

~~  "•   JO 

Fahrenheit:   Multiply  by  nine 

10  == 

~ 

fourths  and  add  32. 

5     "  — 

111     is 

5.   To  convert  Centigrade  to 

0  —  1 

—  • 

Reaumur  :    Multiply    by    four 

5rrz 

—  *            ?ft 

fifths. 

•"-i_: 

—  - 

6.   To  convert  Reaumur  to 

10—= 

Centigrade:   Multiply  by  five 

—  —     25 

15     —  = 

fourths. 

20  = 

=  30 

25     —  = 

30  = 

=—    35 

40  = 

E_« 

FIG.  5.  —  Comparison  of  the  Thermometer  Scales. 


68  THE  NEW  AIR  WORLD 

screen  off  the  direct  and  reflected  sunshine,  and  to 
keep  the  thermometers  dry.  This  shelter  is  a  box 
with  louvered  sides,  constructed  in  such  form  that 
there  is  a  free  circulation  of  air  through  it.  It 
should  be  exposed  in  an  open  space  as  far  away  from 
buildings  as  may  be  convenient,  or  on  a  housetop, 
and  be  as  free  from  shadows  as  possible.  If  such 
position  cannot  be  secured,  then  place  it  on  the 
north  side  of  a  building. 

Comparison  of  Centigrade  and  Fahrenheit.     Only 
Fahrenheit    and    Centigrade    are    in    general    use. 

Figure  5  is  designed  to  enable 
observers  to  convert  tempera- 
ture readings  from  one  scale 
to  the  other  without  resorting 
to  a  mathematical  formula. 
For  precise  reductions  the 
following  rules  apply : 

To  convert  Fahrenheit  to 
Centigrade :  Subtract  32  and 
multiply  by  five  ninths. 

To  convert  Centigrade  to 
Fahrenheit :  Multiply  by  nine 
fifths  and  add  32. 
Humidity   Affects    Health 

FIG.  6.— Dry  and  Wet  Bulb  ,    _  t  -, . 

Thermometers.  and   Complexion.      The 


TAKING  WEATHER  OBSERVATIONS    69 


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70  THE  NEW  AIR  WORLD 


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TAKING  WEATHER  OBSERVATIONS    71 


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72  THE  NEW  AIR  WORLD 

importance  to  health  of  maintaining  a  proper  hu- 
midity in  living  quarters  during  the  winter  months 
and  during  all  months  in  the  arid  and  semi-arid 
regions  of  the  West  is  not  fully  appreciated.  Each 
habitation  should  be  supplied  with  one  to  several 
hygrometers  (Fig.  6),  and  frequent  readings  should 
be  taken  of  the  dry  and  the  wet  bulb  thermometers 
so  as  to  be  familiar  with  the  conditions  under  which 
one  is  living. 

A  relative  humidity  of  between  sixty-five  and 
seventy  per  cent,  should  be  maintained  in  all  liv- 
ing and  sleeping  rooms,  if  one  is  to  escape  colds, 
catarrh,  and  possibly  pneumonia.  Some  nervous 
disorders  are  aggravated  if  not  actually  caused  by 
the  dryness  of  the  air  in  steam  and  other  heated 
apartments  during  the  time  that  the  windows  are 
closed  in  cold  weather.  The  vanity  of  the  female 
sex  is  appealed  to  with  the  statement  that  nothing 
is  more  essential  to  securing  and  preserving  a  good 
complexion  than  the  maintaining  of  a  proper  humid- 
ity in  one's  own  room.  Efficient  and  simple  and 
inexpensive  humidifiers  are  now  coming  on  the 
market.  They  are  almost  as  necessary  to  the  health 
of  a  household  as  stoves  and  furnaces.  Often  a  right 
degree  of  moisture  can  be  created  by  leaving  clean 
water  in  the  bathtub  and  in  all  wash  basins  and  sinks. 


TAKING  WEATHER  OBSERVATIONS    73 

One  may  be  surprised  on  taking  humidity  observa- 
tions to  find  how  quickly  it  increases  in  rooms  two 
or  three  removed  from  the  bathroom  after  water  is 
run  into  the  tub,  and  especially  if  the  shower  spray 
is  turned  on  and  allowed  to  operate  for  a  few  minutes. 

In  cold  weather  we  maintain  the  aridity  of  the 
Sahara  Desert  in  our  hot,  steam-heated  apartments, 
with  a  relative  humidity  of  less  than  thirty  per 
cent.  Is  it  any  wonder  that  when  we  step  from  this 
atmosphere  into  the  cold  outside  air,  with  a  humidity 
of  seventy  per  cent.,  the  violent  change  is  productive 
of  harm,  particularly  to  the  delicate  mucous  mem- 
branes of  the  upper  air  passages,  which  have  been 
irritated  and  their  powers  of  resistance  weakened  by 
the  dryness  within  ?  The  period  of  pneumonia  is  the 
season  of  artificial  heat  in  living  rooms  —  or,  more 
properly  speaking,  the  period  of  indoor  desert  aridity. 

Save  Fuel  by  Moistening  Air.  If  a  room  at  68° 
is  not  warm  enough  for  any  healthy  person  it  is 
because  the  humidity  is  too  low,  and  water  should 
be  evaporated  to  bring  the  moisture  up  to  sixty- 
five  or  seventy  per  cent,  of  saturation.  Water  in- 
stead of  coal  should  be  used  to  make  rooms  com- 
fortable when  the  temperature  has  reached  68°. 
Ten  to  fifteen  per  cent,  of  fuel  could  be  saved  in 
the  heating  of  places  of  habitation  if  the  air  were 


74  THE  NEW  AIR  WORLD 

properly  and  healthfully  humidified.  The  reason 
for  this  is  that  if  the  air  is  dry  the  heat  passes  through 
it  and  warms  it  but  little.  Moisture  stops  the 
radiated  heat  that  would  be  lost,  absorbs  it,  and 
holds  it  at  the  place  where  it  is  needed.  It  has 
precisely  the  same  effect  as  a  soft  wool  blanket 
wrapped  about  the  body  of  each  person.  The  dry 
air  permits  such  a  rapid  evaporation  from  the  hu- 
man body  that  one  may  actually  feel  colder  with  a 

0 

dry  air  heated  to  75°  than  in  a  moist  air  at  66°  or 
68°.  Water  is  cheaper  than  coal,  and  in  this  matter 
much  more  healthful. 

The  cooling  effect  produced  by  a  draught  does 
not  necessarily  arise  from  the  wind  being  cooler,  for 
it  may  be  actually  warmer,  but  arises  from  the 
rapid  evaporation  it  causes  on  the  surface  of  the 
skin.  Vapor  of  water  forms  a  blanket  about  the 
earth  and  prevents  it  from  scorching  during  the  day 
and  freezing  during  the  night. 

How  to  Forecast  Weather  with  Only  an  Aneroid 
Barometer.  No  one  except  an  expert  observer 
should  use  the  mercurial  barometer.  The  aneroid 
will  answer  as  well  for  the  purpose  of  forecasting  from 
a  single  instrument;  it  is  cheaper  and  less  com- 
plicated. First  learn  your  elevation  above  sea  level ; 
then  add  to  the  observed  reading  of  your  instrument 


TAKING  WEATHER  OBSERVATIONS    75 

.10  for  each  one  hundred  feet  elevation.  Note  the  fall 
or  rise  and  the  direction  of  the  wind  and  with  the 
aid  of  the  table  on  page  76  highly  satisfactory  fore- 
casts may  be  made  by  any  intelligent  person.  Skill 
will  come  with  practice.  Write  down  your  fore- 
casts each  day  as  you  make  them  and  the  following 
day  note  in  a  blank  space  left  for  the  purpose  the 
success  or  failure  of  your  effort.  Thus  will  you 
profit  by  your  mistakes. 

As  a  rule  winds  from  the  east  ^quadrants  and 
falling  barometer  indicate  foul  weather,  and  winds 
shifting  to  the  west  quadrants  indicate  clearing  and 
fair  weather.  The  rapidity  of  the  storm's  ap- 
proach and  its  severity  are  indicated  by  the  rate 
and  the  amount  in  the  fall  of  the  barometer.  This 
applies  to  the  Mississippi  Valley  and  eastward  to 
the  Atlantic  Ocean.  Conditions  are  different  in 
the  Rocky  Mountains,  on  the  plateau  of  the  moun- 
tains, and  on  the  eastern  Rocky  Mountain  slope, 
where  precipitation  seldom  begins  until  after  the 
barometer  begins  to  rise  after  a  fall,  and  the  winds 
have  shifted  to  the  northwest. 

Keep  in  mind  that  storms  are  great  atmospheric 
eddies  drifting  from  the  west,  with  the  winds  blow- 
ing cyclonically  toward  the  center ;  that  when  your 
wind  is  northeast  the  center  of  the  storm  is  south- 


76 


TtfE  NEW  AIR  WORLD 


WIND 

DIRECTION 

BAROMETER  REDUCED  TO 
SEA  LEVEL 

CHABACTEB  OF  WEATHER 
INDICATED 

SW.  to  NW. 

30.10    to    30.20  and 

Fair,     with     slight      temperature 

steady. 

changes,  for  1  to  2  days. 

SW.  to  NW. 

30.10    to    30.20  and 

Fair,   followed  within  2  days  by 

rising  rapidly. 

rain. 

SW.  to  NW. 

30.20  and  above  and 

Continued   fair,   with   no   decided 

stationary. 

temperature  change. 

SW.  to  NW. 

30.20  and  above  and 

Slowly  rising  temperature  and  fair 

falling  slowly. 

for  2  days. 

S.   to   SE. 

30.10    to    30.20  and 

Rain  within  24  hours. 

falling  slowly. 

S.  to  SE. 

30.10  to   30.20  and 

Wind  increasing  in  force,  with  rain 

falling  rapidly. 

within  12  to  24  hours. 

S.  to  SW. 

30.00  or  below  and 

Clearing  within  a  few  hours,  and 

rising  slowly. 

fair  for  several  days. 

S.  to  E. 

29.80  or  below  and 

Severe  storm  imminent,  followed, 

falling  rapidly. 

within  24  hours,  by  clearing,  and 

in  winter  by  colder. 

SE.  to  NE. 

30.10   to  30.20  and 

Rain  in  12  to  18  hours. 

falling  slowly. 

SE.  to  NE. 

30.10   to   30.20   and 

Increasing  wind,  and  rain  within 

falling  rapidly. 

12  hours. 

SE.  to  NE. 

30.00  or  below  and 

Rain  will  continue  1  to  2  days. 

falling  slowly. 

SE.  to  NE. 

30.00  or  below  and 

Rain,    with   high   wind,   followed, 

falling  rapidly. 

within    36    hours,    by    clearing, 

and  in  winter  by  colder. 

E.  to  NE. 

30.10  and  above  and 

In  summer,  with  light  winds,  rain 

falling  slowly. 

may  not  fall  for  several  days. 

In  winter,  rain  within  24  hours. 

E.  to  NE. 

30.10  and  above  and 

In  summer,  rain  probable  within 

falling  rapidly. 

12  to  24  hours.     In  winter,  rain 

or  snow,  with  increasing  winds, 

will  often  set  in  when  the  barom- 

eter begins  to  fall  and  the  wind 

sets  in  from  the  NE. 

E.  to  N. 

29.80  or  below    and 

Severe  northeast    gale  and  heavy 

falling  rapidly. 

precipitation;    in  winter,  heavy 

snow,   followed  by  a  cold  wave. 

Going  to  W. 

29.80  or  below    and 

Clearing  and  colder. 

rising  rapidly. 

TAKING  WEATHER  OBSERVATIONS    77 

west  of  you ;  that  when  it  is  east  the  center  is  west ; 
when  it  is  south  the  center  is  north;  when  it  is 
southwest  the  center  is  northeast,  and  when  it  is 
west  or  northwest  the  center  is  east  of  you. 

Difference  between  Weight  and  Pressure  of  the 
Air.  Air  at  sea  level  and  at  32°  temperature  weighs 
one  and  one  third  ounces  per  cubic  foot.  A  room 
twenty  by  twenty  by  ten  feet  contains  some  333 
pounds  of  air.  The  pressure  of  the  air  is  a  quite 
different  thing.  It  is  the  sum  of  the  weights  of  all 
the  cubic  feet  of  air  that  are  stacked  up,  one  on  top 
of  the  other,  clear  to  the  top  of  the  atmosphere. 
This  is  why  the  higher  one  goes,  the  less  the  pres- 
sure of  the  air,  because  there  are  a  less  number  of 
cubic  feet  above.  And  then  each  cubic  foot  weighs 
a  slight  fraction  less  than  the  one  just  beneath  it 
because  the  air  has  expanded.  The  room  afore-men- 
tioned sustains  a  pressure  of  5880  on  its  floor  and  a 
like  pressure  on  its  ceiling,  and  a  half  of  this  pressure 
on  each  of  the  sides  of  the  room.  The  room  does  not 
collapse  because  the  air  exerts  a  like  pressure  on  the 
outside  of  the  room  and  the  two  pressures  are  equal 
—  one  inward  and  the  other  outward. 

The  Principle  of  the  Barometer.  In  1643  some 
Florentine  gardeners  found  that  they  could  pump 
water  only  thirty-three  feet  high.  This  is  because 


78 


THE  NEW  AIR  WORLD 


FIG.  7.  —  Mercu- 
rial Barometer. 
The  glass  tube  on 
right  is  filled  with 
mercury.  With 
the  thumb  over 
the  open  end,  it 
is  reversed  so  that 
its  open  end  rests 
under  the  surface 
in  a  basin  of  mer- 
cury on  the  left, 
and  the  mercury  in 
the  tube  falls  to  n, 
at  which  point  it  is 
sustained  by  pres- 
sure of  the  air  on 
surf  ace  of  the  mer- 
cury in  the  basin. 


the  entire  volume  of  air,  if  it  were 
compressed  to  the  density  of  water, 
would  equal  a  covering  around  the 
earth  of  that  depth.  When  the 
gardeners  first  began  to  work  the 
plungers  in  their  pump  up  and  down 
they  did  not  get  water ;  it  was  nec- 
essary for  them  first  to  pump  out  all 
the  air  in  the  pipe  leading  down  to 
the  water  in  the  well ;  then  the  water 
rose  into  the  vacuum  thus  created, 
and  it  rose  to  a  height  that  just  bal- 
anced the  weight  or  pressure  of  the 
whole  body  of  air  that  rests  upon 
the  earth.  Now,  if  the  atmosphere 
surrounding  the  earth  could  be  re- 
duced to  the  density  of  mercury  it 
would  equal  a  covering  only  thirty 
inches  deep ;  this  is  why  the  mercury 
normally  stands  at  thirty  inches 
high  in  the  vertical  vacuum  tube  of 
the  barometer.  (Figure  7.)  In  the 
complete  barometer  a  graduated 
scale  is  attached  so  as  to  measure 
the  fluctuations  in  the  height  of  the 
mercury.  If  one  were  to  ascend  in 


TAKING  WEATHER  OBSERVATIONS    79 

a  balloon  it  would  be  found  that  the  mercury  would 
steadily  fall  with  increasing  altitude,  until  at  eight- 
een thousand  feet  one  half  of  the  atmosphere  would 
be  left  below  and  the  instrument  would  read  only 
fifteen  inches  instead  of  thirty.  In  ascending  to  the 
top  of  the  Washington  Monument,  555  feet,  the 
pressure  of  the  air  decreases  over  one  half  inch. 

The  barometer  rises  and  falls  with  the  passage  of 
storms  because  wind  movement  displaces  air  and 
causes  it  to  accumulate  at  some  places  and  become 
deficient  at  others,  but  in  order  to  compare  barom- 
eters exposed  at  many  different  elevations  with 
the  view  of  determining  the  geographic  position  of 
storm  centers  —  of  cyclones  and  anti-cyclones  —  it 
is  necessary  to  reduce  all  barometric  readings  to 
sea  level. 

Weather  Records  Turn  the  Scales  of  Justice. 
How  trivial  the  incident  that  may  change  the  whole 
course  of  a  lifetime  and  lead  to  peace  and  happiness 
or  to  discord  and  sorrow !  Likewise  the  parting  of 
the  clouds  and  the  coming  through  of  the  sunshine, 
or  the  moment  of  the  beginning  of  rainfall,  or 
the  amount  of  rain  that  falls  within  a  given 
time,  or  the  direction  of  the  wind,  or  the  velocity 
of  the  wind,  or  the  temperature  of  the  air, 
or  the  depth  of  the  snowfall  literally  thousands  of 


80  THE  NEW  AIR  WORLD 

times  has  furnished  the  evidence  in  courts  of  law 
that  has  turned  the  scales  of  justice  in  civil  suits 
involving  large  sums  of  money,  and  in  criminal 
cases  where  a  prison  sentence  or  the  hangman's 
noose  threatened  the  defendant. 

For  illustration  let  us  say  that  a  ship  breaks  from 
its  mooring,  crashes  into  another  ship  in  the  harbor 
and  sinks  it.  If  the  force  of  the  storm  is  no  greater 
than  has  previously  occurred  in  that  harbor,  the 
first  ship  is  liable  for  the  loss  of  the  second  ship. 
But  if  the  automatically  recording  instruments  of 
the  Weather  Bureau  show  that  at  that  time  the 
velocity  of  the  wind  was  greater  than  ever  had  been 
known  before,  then  the  loss  is  due  to  "an  act  of 
God  "  and  the  ship  that  broke  her  mooring  is  not 
liable  for  damages  to  the  ship  that  was  sunk,  pro- 
vided proper  provision  was  made  for  such  velocity 
of  wind  as  reasonably  might  be  expected  to  occur 
with  the  passage  of  a  storm. 

To  cite  a  case  that  actually  occurred :  A  railroad 
company  was  sued  for  the  loss  of  a  million  dollars' 
worth  of  lumber  that  was  burned,  as  alleged,  by 
sparks  from  one  of  its  locomotives.  Here  came  in 
the  wind  records  of  the  Government  and  proved 
that  at  the  time  of  the  starting  of  the  fire  the  wind 
was  steadily  and  forcefully  blowing  in  a  direction 


TAKING  WEATHER  OBSERVATIONS   81 

opposite  to  what  would  carry  the  sparks  to  the 
lumber,  and  the  company  was  protected  against  an 
unjust  verdict. 

Again  heavy  rain  fell  in  excess  of  the  capacity  of 
the  sewers  of  a  city  to  carry  away  the  water,  and 
private  property  was  damaged  by  the  flood.  In 
this  case  the  city  was  compelled  to  pay  for  the 
damage  to  property,  because  the  records  of  the 
Weather  Bureau  showed  that  previous  rainfalls  had 
been  of  equal  or  greater  amount  in  the  same  period 
of  time,  and  the  city  should  have  constructed  its 
sewers  of  sufficient  capacity  to  carry  away  such 
precipitation  as  experience  showed  was  liable  to 
occur. 

The  writer  was  once  an  expert  witness  in  what 
then  was  a  famous  case.  The  defendant,  a  young 
and  handsome  woman  previously  of  unimpeachable 
character,  was  being  sued  for  divorce.  Two  wit- 
nesses swore  that  they  had  seen  her  come  to  an 
open  window,  facing  south,  at  seven  o'clock  in  the 
morning,  in  a  house  in  which  she  should  not  have 
been,  stand  for  several  minutes  looking  into  the 
garden  upon  which  the  window  faced,  clad  only 
in  her  night  robe.  Unfortunately  the  woman  was 
not  able  to  establish  a  satisfactory  alibi  for  the 
morning  in  question,  and  she  stood  facing  a  terrible 


82  THE  NEW  AIR  WORLD 

calamity  with  no  power  to  establish  her  innocence. 
Her  accusers  had  given  as  a  reason  why  she  stood  so 
long  at  the  open  window  that  the  morning  was 
warm  and  balmy.  But,  fortunately  for  the  inno- 
cent woman,  the  weather  records  came  to  her  de- 
fense when  her  case  seemed  hopeless  and  her  life  was 
about  to  be  blighted  with  a  scandal  from  which  she 
never  would  be  able  to  free  herself,  and  proved  that 
at  the  very  time  when  she  was  supposed  to  have 
been  standing  in  the  open  window  a  torrential  rain 
was  falling  and  a  wind  of  fifty  miles  per  hour  was  beat- 
ing upon  the  outside  of  the  window  panes.  The 
woman  was  acquitted  and  one  of  the  witnesses  spent 
several  hundred  balmy  mornings  behind  prison  bars. 
At  another  time  the  writer  came  into  a  case  where 
a  robber  had  shot  and  killed  a  citizen  who  sur- 
prised him  in  the  committing  of  his  crime.  The 
robber  was  on  trial  for  murder  and  his  lawyers  were 
attempting  to  clear  him  by  the  introduction  of 
evidence  to  prove  that  the  day  was  so  foggy  that 
the  State's  witnesses  had  blundered  and  seized  the 
wrong  man  when  they  chased  the  murderer  around 
a  corner.  The  weather  expert  destroyed  the  only 
evidence  that  tended  to  raise  a  doubt  in  the  mind 
of  the  jury  as  to  the  man's  guilt,  by  testifying  that 
fog  could  come  to  the  surface  of  the  earth  only  when 


TAKING  WEATHER  OBSERVATIONS    83 

the  air  was  abnormally  light  and  the  wind  calm  or 
only  gentle;  while  at  the  time  of  the  murder  the 
barometer  was  unusually  high  and  the  wind  brisk. 
Here  again  the  meteorological  records  aided  in  vindi- 
cating the  right,  and  secured  the  conviction  and 
execution  of  a  brutal  murderer. 

A  remarkable  case  was  that  in  which  a  tramp  was 
being  tried  for  the  murder  of  a  miserly  old  woman 
who  was  believed  to  carry  a  large  amount  of  money 
about  her  person.  The  tramp  came  to  her  door 
and  asked  for  food.  She  took  him  in  and  fed  him 
and  soon  thereafter  he  was  seen  hastily  to  leave  the 
house.  An  hour  after  he  had  gone  the  woman  was 
found  murdered  and  her  clothing  rifled.  The  tramp 
was  overtaken,  found  to  have  a  large  amount  of 
money  of  small  denominations  in  his  pockets,  in- 
dicted, and  placed  on  trial.  The  principal  witness 
for  the  State  was  a  man  who  was  repairing  a  frozen 
water  pipe  in  a  trench  by  the  side  of  the  house  op- 
posite to  that  by  which  the  tramp  entered  and  left. 
He  saw  the  blow  struck,  ran  in  fear  to  his  home,  and 
then  informed  the  police.  In  explaining  how  he 
came  to  see  the  criminal  act,  he  testified  that  he 
climbed  out  of  the  trench  to  get  a  drink  from  a  bucket 
standing  near  by,  and  as  he  raised  the  bucket  his 
eye  came  in  line  with  a  window  of  the  house,  through 


84  THE  NEW  AIR  WORLD 

which  he  witnessed  the  murder.  The  case  seemed 
clear  against  the  tramp,  as  other  witnesses  had  seen 
him  enter  and  leave  the  house  and  positively  recog- 
nized him.  Just  here  his  lawyer  asked  the  trench 
digger  how  long  the  water  bucket  had  been  sitting 
by  the  side  of  the  trench.  The  latter  said  it  had 
been  there  from  7  o'clock  until  10.  Then  the 
weather  records  came  in  to  confound  the  falsifier 
and  to  vindicate  innocence,  for  the  automatic  trac- 
ing of  the  pen  that  records  every  movement  of  the 
temperature  proved  that  the  temperature  had  not 
been  above  zero  any  time  during  the  three  hours  that 
the  bucket  had  been  exposed  and  that  it  contained 
a  solid  chunk  of  ice  if  it  contained  anything.  The 
trench  digger  then  confessed  that  he  himself  was  the 
murderer.  He  had  seen  the  tramp  enter  and  leave 
and  thought  it  a  favorable  opportunity  to  commit 
the  crime  and  put  the  evidence  on  another. 


CHAPTER  VII 
FROST 

THERE  is  nothing  in  the  study  of  the  atmosphere 
that  so  intimately  concerns  the  horticulturist  and 
the  gardener  as  knowledge  of  the  conditions  under 
which  frost  forms,  and  the  methods  that  may  be 
pursued  to  gain  immunity  from  its  disastrous  effects, 
or  to  lessen  the  loss. 

Frost  does  not  necessarily  form  from  air  that  has 
fallen  to  the  freezing  point,  as  many  suppose.  On 
the  contrary,  the  air  ten  feet  or  less  above  the  vege- 
tation may  be  several  degrees  above  freezing  when 
there  is  a  heavy  and  destructive  frost  upon  vege- 
tation. The  fact  is  that  vegetation  radiates  heat 
towards  a  clear  sky  faster  than  does  the  air  and  may 
fall  to  the  freezing  point  or  below;  while  the  air, 
except  the  molecules  actually  in  contact  with  the 
vegetation,  is  considerably  warmer.  Frost  is  not 
frozen  dew.  The  water  vapor  is  precipitated,  or 


86  THE  NEW  AIR  WORLD 

rather  congealed,  upon  the  vegetation  without  pass- 
ing through  the  liquid  state  at  all.  Frost  is  spoken 
of  as  light,  heavy,  and  killing.  Tomato  plants  are 
killed  by  only  a  light  touch  of  frost,  while  fruit 
blossoms  will  stand  several  degrees  of  cold  below 
freezing.  Therefore  the  tomato  grower  would  con- 
sider as  killing  a  frost  that  to  the  fruit  grower  would 
only  appear  as  light. 

The  radiation  of  heat  from  the  earth  is  continuous 
both  day  and  night  when  there  are  no  clouds  to 
obstruct  the  passage  of  the  heat  rays.  The  amount 
received  from  the  sun  during  the  day  is  greater  than 
the  loss  by  radiation  from  the  earth  and  the  tempera- 
ture of  the  air  rises.  After  the  setting  of  the  sun 
the  radiation  of  the  earth  goes  on  but  there  is  no 
incoming  heat  from  the  sun  to  offset  the  loss  and  the 
temperature  of  the  air  falls.  As  previously  stated, 
the  soil  and  vegetation  radiate  faster  than  the  air 
and  the  air  in  immediate  contact  with  the  soil  is 
cooled  by  conduction  to  it.  Thus  over  a  level  plain 
on  a  clear  calm  night  there  is  found  a  relatively  thin 
layer  of  cold  air  near  the  ground,  which  increases  in 
temperature  up  to  two  hundred  or  three  hundred 
feet,  or  which  may  be  only  five  or  ten  feet  deep. 
Over  sloping  ground  the  force  of  gravity  tends  to 
cause  this  thin  surface  layer  of  cold  air  to  move 


FROST 


87 


down  the  slope  and  to  gather  in  depressions  in  some- 
what the  same  manner  as  water  would  move.  Such 
movement  is  called  Air  Drainage.  Of  course  this 
air  is  slowly  gaining  heat  by  compression  as  it  passes 
to  lower  levels,  but  it  is  hugging  closely  to  the  cold 


V 


^ 


-y- 


Te.'npesaturt  ^25  ftet  ofiot*  tote  station 

_._.  Tunpfraturf  $0  feet  at>org  f>cse  ^  tot  ion. 

Temperafure  25  feet  atvve  tvse  jtotioa. 

_____  Temperature  at  Arse  stotton. 


FIG.  8.  —  Continuous  records  of  the  temperature  from  4  P.M.  to  9  A.M.  at 
the  base  and  at  different  heights  above  the  base  of  a  steep  hillside,  show- 
ing the  great  differences  in  temperature  that  sometimes  develop  on  a 
clear,  still  night.  Although  the  temperature  at  the  base  was  low  enough 
to  cause  considerable  damage  to  fruit,  the  lowest  temperature  225  feet 
above  on  the  slope  was  only  51°.  Note  that  the  duration  of  the  lowest 
temperature  was  much  shorter  on  the  hillside  than  at  the  base. — 
Weather  Bureau. 

earth  and  losing  by  conduction  much  or  all  that  it 
thus  gains  by  compression. 

After  a  study  of  the  contour  of  the  region  with  re- 
spect to  air  drainage  the  writer  purchased  a  con- 


88  THE  NEW  AIR  WORLD 

siderable  tract  of  land  near  Rockville,  Montgomery 
County,  Maryland,  and  planted  extensive  orchards 
thereon,  with  the  result  of  harvesting  nine  successful 
crops  of  fruit  in  a  period  of  ten  years  after  the  trees 
became  large  enough  to  bear.  With  the  composition 
and  the  surface  covering  of  the  soil  the  same,  the 
low  places  in  a  field  are  always  the  ones  that  suffer 
most  when  frost  is  possible.  Figure  8  shows  a 
minimum  temperature  of  25°  to  have  occurred  at  the 
base  of  a  steep  hillside  when  on  the  higher  ground 
at  an  elevation  of  but  fifty  feet  the  lowest  tempera- 
ture was  44°,  and  at  two  hundred  and  twenty-five 
feet  up  the  mountainside  the  minimum  was  52°. 

In  selecting  a  location  for  an  orchard  it  is  not  so 
much  a  problem  of  elevation  above  sea  level  as  ele- 
vation above  the  surrounding  region.  The  direction 
in  which  the  slope  faces  makes  little  difference.  The 
prime  consideration  is  to  get  sufficient  air  drainage 
to  gain  the  greatest  protection  against  frost  without 
selecting  land  with  such  a  steep  slope  as  to  furnish 
excessive  soil  drainage  and  which  would  be  diffi- 
cult to  cultivate  and  move  about  upon  in  the  spray- 
ing of  trees  and  in  the  picking  of  fruit.  In  the 
Maryland  orchard  the  elevation  was  only  five 
hundred  feet  above  sea  level  and  only  about  two 
hundred  feet  above  the  surrounding  region,  and 


FROST  89 

the  slope  was  so  gradual  as  almost  to  be  impercepti- 
ble to  one  passing  over  it. 

After  nightfall  the  air  on  mountain  peaks  and  on 
hills  and  ridges  soon  becomes  cooler  than  the  air  at 
the  same  elevation  out  over  the  open  valley,  due  to 
contact  with  the  elevated  earth,  which  radiates  heat 
and  cools  faster  than  the  air. 

Water  vapor  has  a  great  capacity  for  heat.  It  is 
the  most  effective  of  the  various  gases  present  in  the 
atmosphere  in  obstructing  radiation  of  heat  from  the 
earth,  as  well  as  in  absorbing  incoming  radiation 
from  the  sun.  The  night  temperature,  therefore, 
falls  more  slowly  when  the  relative  humidity  is  high 
than  when  it  is  low,  that  is  to  say,  when  the  air  is 
nearer  saturation,  or  nearer  its  dew  point.  Drops 
of  water  that  collect  on  the  outside  of  a  pitcher  of 
ice  water  on  a  warm  day  are  formed  through  the 
chilling  of  the  air  in  contact  with  the  pitcher ;  they 
begin  to  form  as  soon  as  the  temperature  of  the 
pitcher  reaches  the  dew  point  of  the  air,  which 
temperature  varies  in  accordance  with  the  amount 
of  water  vapor  present  in  the  air  at  the  time.  After 
sundown  the  temperature  of  exposed  objects  falls, 
of  some  faster  than  others,  depending  on  their  ca- 
pacities for  radiation.  Vegetation  radiates  freely 
and  often  falls  to  the  dew  point  of  the  air,  at  which 


90  THE  NEW  AIR  WORLD 

time  dew  begins  to  form  on  it  and  continues  to  be 
deposited  as  long  as  the  temperature  remains  above 
freezing.  Now,  here  carefully  note  that  if  the  dew 
point  is  above  32°  the  condensation  of  water  vapor 
in  the  form  of  dew  liberates  latent  heat,  which 
usually  will  be  sufficient  to  check  the  fall  of  tem- 
perature and  prevent  the  formation  of  frost.  If  the 
dew  point  of  the  air  is  32°  or  lower  frost  forms.  If 
the  dew  point  is  very  low  the  temperature  may  fall 
low  enough  to  cause  much  damage  without  the 
formation  of  any  frost.  As  an  example,  if  the  dew 
point  be  20°  and  the  temperature  falls  to  24°  much 
damage  might  be  done  to  growing  crops  and  no 
frost  appear.  This  phenomenon  is  called  black 
frost;  it  seldom  occurs.  From  the  foregoing  it 
might  be  assumed  that  the  possibilities  of  frost  might 
safely  be  forecast  from  an  observation  to  determine 
the  relative  humidity  taken  early  in  the  evening, 
but  unfortunately  experience  has  shown  that  reliance 
cannot  be  placed  in  such  method  of  forecasting,  as 
the  humid  air  of  early  evening  may  be  displaced  by 
much  drier  air  before  the  hour  of  minimum  tem- 
perature the  next  morning. 

One  of  the  best  locations  to  gain  immunity  from 
frost  at  the  critical  period  of  plant  growth  is  im- 
mediately to  the  leeward  of  a  considerable  body  of 


FROST  91 

water.  Wind  blowing  from  a  large  body  of  water 
is  always  heavily  laden  with  moisture,  which  de- 
creases the  rate  of  radiation  both  day  and  night, 
but  especially  during  the  period  of  cold  in  the  early 
morning  when  frost  is  liable  to  occur.  Such  winds, 
largely  affected  by  the  temperature  of  the  water 
over  which  they  have  passed,,  modify  the  tempera- 
tures of  both  day  and  night. 

The  all-important  condition  for  the  formation  of 
frost  is  an  atmosphere  already  cool,  with  a  gentle 
northwest  wind  and  a  clear  sky,  which  condition, 
with  more  or  less  coolness,  always  accompanies  the 
high  barometric  areas  that  follow  the  low-pressure 
areas  of  warmth,  cloudiness,  and  moisture. 

At  an  expense  of  two  millions  of  dollars  per  annum 
the  Government  maintains  some  two  hundred 
observation  stations  of  the  Weather  Bureau,  and 
twice  daily  telegraphs  observations  to  all  the  large 
cities  of  the  nation,  but  unfortunately  in  many 
cases  these  are  not  published  for  the  benefit  of  the 
people  who  could  make  valuable  use  of  them.  The 
Bureau's  own  deductions  from  these  observations, 
in  the  form  of  forecasts  and  warnings,  are  extremely 
valuable,  but  an  even  greater  service  could  be  ren- 
dered the  public  by  neatly  lithographing  an  evening 
weather  map  and  mailing  it  from  all  large  cities  each 


92  THE  NEW  AIR  WORLD 

night,  so  that  every  intelligent  person  whose  business 
is  affected  by  the  weather  could,  through  a  study  of 
the  chapter  on  Forecasting  in  this  book,  judge  for 
himself  as  to  the  effect  that  the  coming  weather  may 
have  on  his  particular  interests.  One  could  then 
watch  the  movements  of  the  high  barometric  areas 
and  the  low  areas  and  become  weatherwise  himself, 
and  he  who  studied  these  charts  the  most  diligently 
would  have  an  advantage  over  less  progressive 
competitors. 

Evaporation  goes  on  at  all  temperatures,  even 
below  freezing  and  from  solid  ice,  its  rate,  of  course, 
being  diminished  by  low  temperatures.  At  times, 
in  spring  or  fall,  the  temperature  of  the  air  over 
rivers,  when  there  is  little  wind,  falls  so  far  below 
the  temperature  of  the  water  that  the  water  vapor 
rising  from  the  river  by  evaporation  is  quickly 
condensed  in  the  form  of  fog,  which  may  cover  a  part 
or  all  of  the  low  contiguous  land,  checking  radiation 
and  preventing  a  further  fall  in  temperature. 

In  valleys  near  the  ocean,  fog  sometimes  drifts  in 
from  the  water  when  frost  is  imminent  and  prevents 
its  formation.  On  nights  with  fog,  contrary  to  the 
usual  condition,  the  hillsides  are  always  colder  than 
the  lowlands,  unless  the  fog  extends  high  enough  to 
cover  them. 


FROST  93 

In  1891-1894  the  writer,  in  studying  the  conditions 
under  which  frost  forms  on  the  cranberry  bogs  of 
Wisconsin,  was  impressed  with  the  fact  that  the 
occurrence  of  frost  on  a  given  field  depended  as  much 
on  the  character  of  the  surface  and  its  covering 
as  it  did  on  the  temperature  of  the  air  a  few  feet 
above,  one  place  receiving  an  injurious  frost,  another 
a  light  frost,  and  still  another  none  at  all,  while  each 
had  the  same  conditions  as  to  temperature,  wind 
velocity  and  direction,  and  all  were  at  the  same  ele- 
vation, so  that  the  differences  could  not  be  accounted 
for  by  air  drainage. 

In  one  case  the  marsh  was  cleanly  cultivated 
and  covered  with  sand,  in  another  there  was  clean 
cultivation  but  no  sand,  and  in  still  another  case 
there  was  a  thick  growth  of  vegetation.  As  the 
result  of  a  long  series  of  observations  conducted  by 
Professor  H.  J.  Cox,  working  under  the  directions 
of  the  writer,  minimum  thermometers  were  placed 
among  the  vines  over  newly  sanded  surfaces  in  two 
marshes,  one  at  Cranmoor  and  one  at  Mather, 
Wisconsin.  The  locations  selected  for  this  inquiry 
represented  the  best  results  that  could  be  secured 
from  sanding,  draining,  and  cultivating.  Comparison 
was  made  at  each  marsh  between  the  readings  taken 
close  to  the  vines  of  the  clean  part  of  the  marsh  and 


94  THE  NEW  AIR  WORLD 

those  taken  close  to  the  surface  over  the  unsanded 
peat  bog.  The  average  lowest  night  temperature 
over  the  sand  for  the  four  months  was  5.9°  higher 
than  over  the  peat  at  Cranmoor,  and  4.2°  at  Mather. 
On  one  night  the  minimum  over  the  surface  at  Cran- 
moor was  12°  higher  than  over  the  peat,  while  at 
Mather  a  difference  of  nine  degrees  was  recorded  on 
another  night. 

Through  cultivation  the  marsh  may  be  kept  free 
from  weeds,  moss,  or  other  rank  growth,  thus  per- 
mitting the  sun's  rays  to  reach  the  soil  and  increase 
its  temperature  during  the  day,  while  a  growth  of 
thick  vegetation  screens  the  soil  from  the  sun's  rays, 
and  there  is  consequently  less  heat  in  the  latter  soil 
to  be  given  out  during  the  hours  of  low  temperature 
at  night.  Drainage  lowers  the  specific  heat  of  the 
soil  and  decreases  the  cooling  effect  of  evaporation. 
Therefore,  under  sunshine,  the  dry  soil  becomes 
warmer  than  the  wet  and,  whether  or  not  it  has 
a  greater  quantity  of  heat  to  give  off  at  night,  it  has  a 
higher  temperature  and  therefore  radiates  more  freely 
to  the  air  above.  A  covering  of  sand  likewise  lowers 
the  specific  heat  of  the  surface  and  thereby  causes  it 
to  gain  a  higher  temperature  during  the  day  than 
an  unsanded  surface  receiving  the  same  solar  rays. 
It  therefore  radiates  more  rapidly  at  the  critical  time 


FROST 


95 


when  heat  is  needed  to  prevent  the  temperature  of 
vegetation  from  falling  to  the  freezing  point  and 
gaining  a  deposit  of  frost. 


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FIG.  9.  —  Continuous  records  of  the  temperature  5  feet  and  35  feet  above 
ground  on  a  tower  in  a  pear  orchard.  Note  the  large  difference  in  tem- 
perature at  the  two  levels  before  the  orchard  heaters  were  lighted  at 
4  A.M.  By  5  A.M.  the  temperature  was  practically  the  same  at  the 
two  levels,  showing  that  the  heat  from  the  burning  oil  had  been  nearly 
all  expended  in  raising  the  temperature  of  the  air  within  35  feet  of  the 
ground.  This  point  is  further  illustrated  by  the  fact  that  at  5  A.M. 
when  most  of  the  heaters  were  extinguished,  the  temperature  at  the 
5-foot  level  fell  rapidly,  while  it  remained  practically  stationary  at  the 
35-foot  level.  —  Weather  Bureau. 

In  many  orchards  in  the  Rocky  Mountain  States, 
where  fruit  growing  is  highly  profitable  and  the 
injury  from  frost  more  than  probable  every  year,  an 
extensive  use  is  made  of  oil  and  other  fuel-burning 
heaters  between  the  rows  of  trees.  Those  who 
wish  further  information  with  regard  to  this  matter 


96 


THE  NEW  AIR  WORLD 


should  send  to  the  Weather  Bureau,  Washington, 
D.  C.,  for  Farmers'  Bulletin  No.  1096.  At  first 
thought  it  would  seem  that  heat  so  applied  would 
be  blown  away  or  instantly  escape  upward.  But 
on  frosty  nights  there  is  not  much  wind ;  if  there  is, 
there  is  little  danger  from  frost.  And  then,  as 


FIG.  10.  —  Average  dates  of  last  killing  frost  in  spring. 

previously  stated,  on  such  nights  there  is  what  is 
called  temperature  inversion,  and  the  temperature 
actually  rises  with  the  first  few  feet  of  ascent,  and 
the  heated  air  soon  reaches  air  of  its  own  temperature, 
when  no  further  ascent  occurs.  When  the  air 
forty  feet  from  the  ground  is  ten  degrees  warmer 
than  it  is  around  and  in  contact  with  vegetation, 
as  often  occurs  on  frosty  nights,  the  heat  from  the 


FROST 


97 


fires  is  nearly  all  expended  in  raising  the  temperature 
of  the  air  within  this  forty  feet.  Figure  9  furnishes 
the  result  of  an  experiment  illustrating  the  cor- 
rectness of  the  foregoing  theory. 


FIG.  11.  —  Average  dates  of  first  killing  frost  in  fall. 

Figures  10  and  11  show  the  average  dates  of  the 
last  killing  frost  in  spring,  and  of  the  first  killing 
frost  in  fall. 


CHAPTER  Vin 
WIND  AND  PRESSURE   OF  THE  GLOBE 

CAUSE    OF    LOCAL    WINDS   AND    OF    GENERAL    CIRCULATION 

^General  Circulation.  Differences  in  temperature, 
changing  the  specific  gravity  of  the  air,  are  the  cause 
of  the  general  circulation  of  the  atmosphere  about 
the  earth,  modified  by  the  rotation  of  the  earth; 
likewise  the  local  circulation  between  land  and 
water  is  caused  by  the  different  quantities  of  heat 
radiated  by  the  two  widely  differing  forms  of  mat- 
ter, each  attaining  to  a  different  temperature  under 
the  influence  of  the  same  solar  radiation ;  and  the 
inflow  of  winds  to  the  cyclone  and  the  outflow  from 
the  anti-cyclone  are  due  to  the  same  forces  that  cause 
the  general  and  the  local  circulations. 

If  there  were  no  difference  in  temperature  between 
the  equator  and  the  poles  the  atmosphere  would  soon 
adjust  itself  in  accordance  with  the  laws  of  gravity, 
modified  by  the  centrifugal  force  developed  from 
the  rotation  of  the  earth,  and  the  atmosphere  for- 


PRESSURE  OF  GLOBE  99 

ever  would  be  at  rest  relative  to  the  earth,  moving 
with  it  as  if  it  were  a  part  of  the  solid  sphere  through- 
out its  diurnal  rotation  on  its  axis  and  its  annual 
movement  about  the  sun.  But  there  is  a  decided 


PROBABLY  6  MILES  HIGH 


SE  TRADE  WINDS EQUATOR NE  TTZAPE  WINDS 


FIG.  12.  — Trade  wind  circulation  and  reason  for  belts  of  high  pressure 
at  latitudes  30°  N.  and  S.  that  extend  around  globe  as  shown  by 
Figure  13. 

difference  in  temperature  between  the  equator  and 
the  poles  and  between  land  and  water  surfaces; 
hence  a  general  circulation,  modified  and  distorted 
by  numerous  local  movements,  which,  in  turn,  may  be 
modified  by  the  height  of  hills  and  mountains  and 
the  direction  of  their  trend. 

Let  us  trace  a  current  of  air  through  its  course  as 
shown  in  Figure  12  and  the  reason  for  the  blowing  of 
the  trade  winds  will  be  apparent,  as  will  the  reason 
for  the  location  of  a  belt  of  high  pressure  at  latitudes 
30°  north  and  south  encircling  the  globe.  At  the 
equator  there  is  a  belt  of  calms.  Here  the  air 
gently  ascends  under  the  intense  heat  of  vertical 


100  THE  NEW  AIR  WORLD 

sunshine.  It  is  humid,  for  there  is  much  water 
surface  in  the  region  of  the  equator,  and  the  air 
carries  vast  quantities  of  water  vapor  aloft,  later  to 
be  precipitated  as  torrential  rains  in  the  Tropical 
Zone,  as  the  air  cools  by  expansion  in  its  ascent. 
This  air  expands  or  bulges  upward  and  overflows 
aloft  northward  and  southward,  causing  low  air 
pressure  at  the  equator,  because  of  the  quantity 
of  air  moved  to  other  latitudes,  which  more  than 
compensates  for  the  amount  banked  up  over  the 
equator  by  the  centrifugal  force  of  the  earth's 
rotation. 

Since  air,  passing  away  from  the  equator,  must 
pass  successively  over  parallels  of  latitude  having 
less  easterly  velocity  than  that  with  which  it  started 
its  journey,  it  runs  ahead  of  the  earth,  and,  relative 
to  the  surface  of  the  earth,  has  a  direction  from  the 
southwest  north  of  the  equator,  and  from  the  north- 
west south  of  the  equator.  Our  current  was  divided 
at  an  altitude  probably  of  six  miles  above  the  equa- 
tor, one  half  following  the  northern  and  the  other 
half  the  southern  circuit.  It  was  cooled  by  ele- 
vation and  by  radiation  outward  to  space  and  as  a 
result  gained  in  weight  and  gradually  descended, 
reaching  the  earth  at  about  latitudes  30°  north  and 
south,  and  causing  an  accumulation  of  air  at  those 


PRESSURE  OF  GLOBE  101 

latitudes  and  the  belt  of  high  pressure  that  irregu- 
larly surrounds  the  earth.  In  descending  in  the 
belt  the  air  breaks  up  into  a  number  of  anti-cyclonic 
systems,  sub-permanent  highs  or  Centers  of  Action, 
which  have  so  much  to  do  with  initiating  the  mi- 
gratory Highs  and  Lows  that  create  the  weather  of 
the  earth,  as  will  be  fully  explained  in  the  Chapter 
on  Weather  Forecasting.  The  intensity  of  these  cen- 
ters of  action  is  modified  and  their  geographic  positions 
shifted  with  change  of  season.  (See  Charts  1  and  2.) 
Trade  Winds.  But  to  return  to  the  current  that 
we  left  as  it  divided  above  the  equator  (Figure  12) 
and  descended  on  an  inclined  plane  to  latitudes  30° 
north  and  south.  It  is  cooler  and  dryer  and  heavier 
than  when  it  started  to  ascend  and  it  has  lost  the 
thousand  miles  per  hour  and  more  easterly  velocity 
that  it  had  at  the  equator  and  now  only  has  the 
velocity  that  belongs  to  latitude  30°;  therefore  as 
it  moves  toward  the  equator  from  either  side  it  lags 
behind  latitudes  whose  easterly  velocity  is  greater, 
and  it  takes  up  a  direction  partly  toward  the  west, 
which,  relative  to  the  earth,  makes  it  a  northeast 
wind  in  the  Northern  Hemisphere  and  a  southeast 
wind  in  the  Southern  Hemisphere.  And  thus  is 
established  a  circulation  the  lower  part  of  which  is 
known  as  the  "trade  winds."  (Figure  13.) 


102 


THE  NEW  AIR  WORLD 


Navigators  profit  largely  by  availing  themselves 
of  the  west  winds  in  the  middle  latitudes  and  of  the 
east  winds  in  the  tropics.  To  the  daring  and  per- 


Polar  Calms 
Low  Pressure  due  to  Rotation 


Zone  of  West  Winds 

Driven  North  by  High  Pressure  South  and  deflected  towards  East 
by  Rotation  of  Earth 


High  Pressure  Belt  of  Calms 
Due  to  Settling  Down  from  Aloft  of  Anti-Trade  Winds 

-"""  ^x--*  «<-"   N.  E.  Trade  Winds   ^  «-^   ^ 
Driven  Outward  from  the  High  Pressure  to  the  North 


lO'l 


0 

Equatorial  Calms 

10*5 

Low  Pressure  due  to  Heat  and  Ascending!  Currents 

10*5 

*\  *\  "-*»     S.  E.  Trade  Winds    **-^    ^-v.    * — 
Driven  Outward  from  the  High  Pressure  to  the  South 


25*SJ 


UO*S 


High  Pressure  Belt  of  Calms 
Due  to  Settling  Down  from  Aloft  of  Anti-Trade  Winds 


4O*Sj 


"**•*    ^-*    Zone  of  West  Winds  ^»    ^* 

Driven  South  6y  High  Pressure  North  and  deflected  towards  East 

by  Rotation  of  Earth 


jo's- 


70'S. 


Polar  Calms 
Low  Pressure  due  to  Rotation 


FIG.  13.  —  Average  surface  winds  and  pressure  of  the  globe. 

sistence  of  Columbus,  and  the  force  and  constancy 
of  the  trade  winds  which  blew  him  westward,  we 
owe  the  discovery  of  America. 

Winds  of  Middle  Latitudes.    Now  study  Figure 
12  and  associate  the  information  it  conveys  with 


PRESSURE  OF  GLOBE  103 

that  of  Figure  13,  and  observe  that  from  the  two 
belts  of  high  pressure  the  air  is  pushed  outward  on 
both  sides.  In  each  case  it  starts  as  a  true  north  or 
south  wind,  but,  due  to  the  rotation  of  the  earth, 
is  always  and  everywhere  deflected  to  the  right  in  the 
Northern  Hemisphere  and  to  the  left  in  the  Southern 
Hemisphere,  and  this  deflection  increases  until  what 
started  as  a  poleward  wind  in  the  middle  latitudes 
soon  becomes  almost  a  due  west  wind.  In  this  region 
of  west  winds  cyclonic  storms  are  more  frequent  than 
in  any  other  part  of  the  globe.  Now  get  clear  in  the 
mind  the  fact  that  no  matter  what  may  be  the  direc- 
tion of  the  wind  inside  a  cyclonic  or  anti-cyclonic 
whirl  (often  one  thousand  miles  in  diameter) ,  the  whirl 
is  carried  toward  the  east  by  the  general  drift  from  the 
west  of  the  winds  between  latitudes  30°  and  60°,  and 
toward  the  west  in  the  region  of  the  trade  winds. 

Low  Barometer  at  the  Poles.  Even  though  the 
air  is  contracted  and  rendered  denser  by  the  great 
cold  of  the  Arctic  regions,  the  pressure  remains  low 
because  of  the  quantity  of  air  driven  equatorward  by 
the  centrifugal  force  both  of  the  earth  and  of  the 
winds  themselves  as  they  run  ahead  of  the  earth 
and  encircle  the  globe  in  the  middle  latitudes. 

Data  too  Meager  to  Show  Full  Circulation  Aloft 
of  the  Atmosphere  of  the  Globe.  Many  charts 


104  THE  NEW  AIR  WORLD 

have  been  published  in  the  attempt  to  show  how  the 
atmosphere  circulates  below  and  aloft  through  the 
whole  world.  They  only  have  speculative  value, 
as  our  knowledge  is  too  limited  to  permit  us  to  un- 
ravel the  complexities  of  all  the  upper  movements. 

Rain  Winds  of  the  Tropics.  The  trade  winds, 
mostly  moving  over  water  surfaces,  are  laden  with 
moisture,  but,  gaining  temperature  as  they  move 
towards  the  equator,  their  capacity  to  hold  water 
vapor  steadily  increases,  and  therefore  they  do  not 
become  rain  winds  unless  forced  to  ascend  by  the 
interposition  of  mountains,  or  until  cooled  by 
ascension  at  the  equator.  In  no  part  of  the  world 
does  the  air  rise  so  steadily  and  in  such  great  volume 
as  in  the  equatorial  belt  of  calms  and  low  pressure. 
Hence  this  is  the  region  of  greatest  rainfall.  Dur- 
ing the  two  rainy  seasons,  spring  and  fall,  the  day 
opens  clear;  near  midday  the  clouds  gather  and 
rain  falls  early  in  the  afternoon;  after  which  it 
quickly  clears.  This  is  so  regular  a  program  that 
one  lays  his  plans  accordingly.  There  is  almost  no 
rain  in  December  and  January ;  this  is  because  the 
belt  of  calms  and  the  inflowing  trade  winds  move 
northward  and  southward  with  the  migrations  of 
the  sun,  and  in  December  and  January,  the  sun  be- 
ing far  south,  the  northern  trades,  with  their  rain- 


PRESSURE  OF  GLOBE  105 

less  winds,  cover  the  equator  and  the  region  formerly 
occupied  by  the  belt  of  calms.  In  midsummer  the 
sun  is  far  north  and  then  the  southern  trades  move 
up  and  give  dryness  to  the  equator.  In  the  northern 
trades,  of  the  moderate  amount  of  rain  that  falls, 
the  greater  quantity  falls  in  summer ;  in  the  southern 
trades  the  order  is  reversed. 

Rain  of  the  High-Pressure  Belts  and  of  the  Regions 
of  West  Winds.  In  the  high-pressure  belts  the 
air  is  settling  down  and  gaining  heat  by  compression 
and  there  is  not  much  horizontal  movement.  These 
are,  therefore,  regions  of  but  little  rainfall,  and  all 
the  great  deserts  occur  in  or  near  them.  The  belts 
of  west  winds  are  the  regions  of  most  frequent 
cyclonic  activities.  Here  the  rainfall  is  quite  equally 
distributed  throughout  the  year  and  is  the  result  of  the 
mixing  of  the  air  by  storms  and  its  cooling  by  expan- 
sion as  it  is  carried  upward  in  the  migrating  whirl. 

Circulation  between  Continents  and  Oceans.  In 
Chapter  X,  under  the  sub-caption  "  Influence  of 
Continents  and  Oceans  on  Climate ",  the  circulation 
between  them  is  well  explained.  In  general  the 
movement  is  from  the  continent  to  the  oceans  in 
winter,  with  the  air  flowing  inward  aloft  to  settle 
down  and  take  the  place  of  that  which  passes  out  to 
sea.  In  summer  the  directions  are  reversed. 


106  THE  NEW  AIR  WORLD 

Daily  Variation  in  Coastal  Winds.  In  summer, 
when  there  are  no  forceful  storm  winds  blowing 
steadily  from  one  direction  for  several  hours  at  a 
time,  there  will  daily  spring  up  gentle  to  fresh  winds 
from  the  surface  of  oceans  and  large  lakes  to  the  land, 
because  of  the  influence  of  the  sun's  rays  in  heating 
the  land  to  a  higher  temperature  than  it  does  the 
water.  These  winds  will  not  appear  on  cloudy  days 
and  they  will  extend  inland  but  a  few  miles. 

Monsoon  Winds.  During  winter  the  vast  con- 
tinent of  Eurasia  (Europe  and  Asia)  cools  to  such 
an  extremely  low  temperature  as  to  develop  a  High, 
or  center  of  action,  of  great  energy  and  extent,  which 
drives  a  steady  dry  monsoon  into  the  Indian  Ocean 
and  China  Sea.  Unlike  the  trade  winds,  these  winds 
reverse  their  direction  in  the  summer;  then  the 
intense  heat  of  the  continent  to  the  north  develops 
an  extensive  Low,  which  draws  the  ocean  winds  in- 
land and  extends  its  influence  so  far  south  as  to 
attract  the  southeast  trade  winds  of  the  Southern 
Hemisphere  and,  turning  them  so  that  they  flow 
from  the  southwest,  continue  them  far  into  the 
interior  of  Asia.  Since  the  summer  monsoon  blows 
from  a  tropical  sea  it  conies  heavily  laden  with 
water  vapor  and  as  it  rises  over  the  mountains  of 
the  great  Himalayan  system  copious  rains  are 


PRESSURE  OF  GLOBE  107 

precipitated.  In  Australia,  Africa,  South  America, 
and  some  parts  of  the  North  American  continent 
monsoon  influence  in  various  degrees  is  felt,  but  in 
no  place  is  the  monsoon  so  important  as  in  the  coun- 
tries bordering  the  Indian  Ocean.  (Charts  15  and  16. ) 

Fohn  Winds.  This  is  a  hot  wind  that  sometimes 
blows  down  a  mountain  side  in  the  Alps.  In  the 
Rocky  Mountains  it  is  called  the  Chinook  Wind.  It 
is  caused  by  moisture-laden  air  being  drawn  over  a 
high  mountain  so  quickly  that  the  heat  liberated 
in  condensation  does  not  have  time  to  escape  by 
radiation.  The  air  cools  by  expansion  as  it  ascends 
on  the  west  side  of  the  mountain,  but  it  gains  this 
all  back  by  compression  as  it  descends,  and  it  has 
added  to  its  temperature  much  of  the  heat  of  con- 
densation. It  is  dry  and  greedily  evaporates  snow 
from  the  ground  in  winter,  clearing  off  a  deep  cover- 
ing within  a  few  hours. 

How  Winds  Are  Deflected  by  Earth's  Rotation. 
Every  free-moving  thing,  whether  wind  or  projectile, 
is  deflected  to  the  right  of  its  initial  direction  by  the 
rotation  of  the  earth  in  the  Northern  Hemisphere 
and  to  the  left  in  the  Southern  Hemisphere,  unless 
the  object  be  moving  exactly  along  the  line  of  the 
equator.  Winds  moving  inward  to  a  Low  are 
therefore  so  deflected  as  to  cause  the  cyclone  to 


108 


THE  NEW  AIR  WORLD 


gyrate  in  a  direction  contrary  to  the  movements  of 
the  hands  of  a  watch.  In  an  anti-cyclone  the  move- 
I"— ^.^  ment  is  with 

the  watch.  In 
the  Southern 
Hemisphere 
these  wind  di- 
rections are  re- 
versed. 

Figure  14 
gives  an  illus- 
tration of  what 
would  be  the 
movement  of 

a  non-rotating  earth.  air    inward    to 

a  cyclone  on  a  non-rotating  earth.  The  winds 
would  blow  along  radial  lines  for  a  time,  but, 
converging  together  as  they  began  to  ascend,  they 
doubtless  would  soon  set  up  a  gyration  about  the 
center.  On  a  non-rotating  earth  this  gyration  would 
be  clockwise  as  often  as  it  would  be  anti-clockwise, 
but  on  a  rotating  earth  the  gyration  can  be  in  but 
one  direction.  (Figure  15.)  Even  tornadoes,  whose 
diameters  of  rotation  are  never  but  a  few  hundred 
feet,  obey  this  law.  In  little  dust  whirls,  in  which  the 
movements  of  air  maybe  comprehended  from  the  mo- 


PIG.  14.  —  How  winds  would  blow  into  a  cyclone  on 


PRESSURE  OF  GLOBE 


109 


tion  of  the  trash  that  is  whirled  about  and  which  are 
tornadoes  in  miniature,  the  direction  of  gyration  may 
be  either  way. 
They  are  too 
small  for  the 
deflecting  force 
to  be  appre- 
ciable, and  it 
may  be  that 
the  tornado  is 
forced  to  take  its 
direction  of 
gyration  from 

the    Cyclone    in   FIG.  15.  — Deflection   of   wind  due  to    earth's 

whose  southeast  rotation> 

quarter  it  has  its  origin. 

How  Wind  Velocity  Increases  with  Altitude. 
Figure  16  shows  how  the  velocity  of  the  wind  in- 
creases with  elevation  in  the  free  air  up  to  five 
thousand  meters  (about  three  miles).  The  average 
for  the  year,  for  the  summer  and  for  the  winter,  is 
given.  It  increases  most  rapidly  up  to  six  hundred 
meters  in  summer  and  up  to  eight  hundred  meters  in 
winter.  From  these  two  heights  there  is  a  steady 
and  pronounced  slowing  down  of  the  wind  up  to 
one  thousand  meters ;  after  which  it  increases  up  to 


110 


THE  NEW  AIR  WORLD 


five  thousand  meters,  and  how  far  beyond  we  know 
not.     In  winter  there  is  a  singular  acceleration  of 


Meter. 


4500 


4000 


3500- 


3000 


2500- 


1800 


1600 
1400 
1200 

1000 
800 
600 

400 
270 


36789 
Velocity,  meters  per  second 


FIG.  16.  —  Annual,  summer,  and  winter  wind  velocities,  with  altitude. 
1,  1850  feet;  2,  2467  feet;  3,  3083  feet;  4, 15,417  feet. 

velocity  in  the  stratum  between  two  thousand  and 
twenty-five  hundred  meters  and  then  no  increase  for 


PRESSURE  OF  GLOBE  111 

the  next  five  hundred  meters;  after  which  there  is 
a  uniform  and  steady  gain  up  to  five  thousand  meters. 
Starting  at  two  hundred  and  seventy  meters,  the 
average  velocity  for  the  year  is  3£  meters  per  second, 
or  about  7i  miles  per  hour.  At  five  thousand  meters 
altitude  the  average  for  the  year  is  Hi  meters  per 
second,  or  about  27  miles  per  hour. 


CHAPTER  IX 

HOW  TO   FORECAST  FROM  THE  DAILY 
WEATHER  MAP 

IT  IS  NOT  DIFFICULT  TO  BECOME  WEATHERWISE  AND 
THEREBY  TO  GAIN  ADVANTAGES  IN  HEALTH,  HAP- 
PINESS, AND  BUSINESS 

THE  person  who  will  take  the  time  to  learn  to  in- 
terpret the  daily  weather  map  has  a  decided  ad- 
vantage over  those  who  are  less  progressive.  The 
maps  may  be  secured  by  applying  to  any  Weather 
Bureau  station.  Many  members  of  commercial 
associations,  having  the  advantage  of  seeing  the  large 
glass  weather  map  that  is  made  each  morning  by  an 
observer  of  the  Weather  Bureau  and  displayed  on  the 
floor  of  the  association,  have  become  expert  weather 
forecasters.  The  value  of  the  principal  crops  of 
the  country  is  largely  influenced  by  the  weather, 
as  are  the  prices  of  transportation  and  industrial 
stock ;  and  there  is  hardly  a  business  that  directly  or 
indirectly  is  not  influenced  by  the  prospects  of  com- 
ing weather. 


HOW  TO  FORECAST  WEATHER      113 

Vessel  masters,  long  accustomed  to  forecast  the 
near  approach  of  storms  from  the  action  of  their 
"  glass  "  (barometer),  now  have  learned  that  the 
daily  weather  map  shows  them  at  a  glance  the 
height  of  not  one  but  of  many  barometers  scattered 
over  a  wide  area  and  read  at  the  same  moment  of 
time.  They  see  that  the  direction  and  the  force 
of  the  wind  are  the  results  of  differences  hi  air  pres- 
sure; that  the  air  flows  from  a  region  where  the 
air  pressure  is  great,  that  is  to  say,  where  the  barom- 
eters are  high,  towards  a  region  where  the  pres- 
sure is  less,  or  where  the  barometers  are  low;  and 
that  the  velocity  of  the  wind  will  be  in  proportion 
to  the  difference  in  the  pressure  of  the  air.  Coast- 
wise and  lake  shipping  are  therefore  not  only  affected 
by  the  forecasts  made  by  the  Weather  Bureau  but 
by  the  forecast  made  by  the  masters  themselves 
when  they  can  get  access  to  the  daily  weather  map. 
Their  own  lives  and  the  lives  and  property  of  others 
are  in  their  keeping.  But  the  great  mass  of  intel- 
ligent people  have  no  idea  of  the  methods  employed 
in  the  making  of  the  weather  map  and  of  the  many 
and  widely  diversified  uses  to  which  a  study  of  its 
data  would  lead. 

One  first  must  learn  of  the  simple  manner  in  which 
the  map  is  constructed ;    then,  by  a  comparison  of 


114  THE  NEW  AIR  WORLD 

the  map  each  day  with  the  preceding  chart,  he  soon 
will  be  able  to  detect  the  beginning  of  storms,  trace 
them  through  their  various  migrations  as  they  cross 
the  continent  and  finally  pass  out  to  sea,  bidding 
them  bon  voyage  as  they  go  in  quest  of  a  more 
eastern  continent  on  which  to  bestow  their  blessings 
of  rain  and  active,  purified  air;  or,  as  it  often  may 
happen,  shuddering  for  the  fate  of  the  mariner  who  is 
caught  in  their  fierce  vortical  whirls,  and  for  the  land 
areas  that  may  be  laid  waste  by  their  gyrating  force. 
How  the  Weather  Map  Is  Made.  At  8  A.M. 
to-day  Washington  time,  which,  by  the  way,  is 
about  seven  o'clock  at  Chicago,  six  at  Denver,  and 
five  at  San  Francisco,  the  observers  at  some  two 
hundred  stations  in  the  United  States  and  contiguous 
territory  were  taking  their  observations  and  from 
carefully  standardized  instruments  noting  the  con- 
ditions of  the  atmosphere.  By  8 :  20  A.M.  the  ba- 
rometers at  each  station  have  been  reduced  to  sea 
level,  that  is  to  say,  they  have  been  made  to  read 
what  they  would  if  they  were  located  at  the  level 
of  the  ocean.  Thus  differences  in  air  pressure  that 
are  due  to  differences  in  elevation  are  eliminated, 
so  that  they  may  not  obscure  those  due  to  storm 
conditions.  Then,  for  purposes  of  brevity  and  ac- 
curacy, the  observations  are  reduced  to  cipher  form, 


•»b  -i* 

>!  i si 

lit  111  I 


HOW  TO  FORECAST  WEATHER      115 

and  each  filed  at  the  local  telegraph  office.  During 
the  next  thirty  or  forty  minutes  the  observations, 
with  the  right  of  way  over  all  lines,  are  speeding  to 
their  destinations,  each  station  contributing  its  own 
report,  and  receiving  in  return  such  observations 
from  other  stations  as  it  may  require.  The  ob- 
servations from  all  stations  are  received  at  such 
important  centers  as  Washington,  New  York, 
Chicago,  and  other  large  cities  having  Weather 
Bureau  stations,  and  from  these  centers  daily  weather 
maps  are  printed  and  issued  at  11  A.M.  each  day. 

Now  turn  to  Chart  3.  Heavy  black  lines  (isobars, 
meaning  equal  pressure)  are  drawn  through  places 
having  the  same  barometric  reading.  The  readings 
are  omitted  from  the  printed  Chart.  By  drawing 
lines  for  each  difference  of  one  tenth  of  an  inch, 
the  high  and  the  low-pressure  areas  (called  Highs 
and  Lows)  are  soon  inclosed  in  their  proper  circles. 
These  lines  run  in  oval  or  circular  form,  indicating 
that  storms  operate  in  the  form  of  great  atmospheric 
eddies ;  that  there  are  central  places  of  attraction 
towards  which  the  air  is  drawn  if  the  disturbance  be 
a  low-pressure  area,  with  its  usual  accompaniments 
of  warm,  moist,  and  often  rainy  weather,  and  from 
which  the  air  is  driven  if  it  be  a  high-pressure  area, 
with  cool,  settled  weather. 


116  THE  NEW  AIR  WORLD 

The  word  "  High  "  is  written  inside  the  isobar 
marked  30.6,  located  in  southern  Oregon,  and  the 
same  word  is  written  inside  the  isobar  marked  30.4, 
located  on  the  South  Atlantic  coast,  and  also  inside 
the  isobar  30.04,  which  traverses  Nova  Scotia.  These 
are  the  regions  of  great  air  pressure.  The  word 
"  Low  "  is  written  at  the  center  of  the  area  inclosed 
by  the  isobar  29.6,  which  is  situated  in  the  State  of 
Iowa.  The  latter  is  the  region  of  least  pressure. 
Sometimes  there  are  several  such  regions  shown  on 
the  weather  map. 

Why  the  Wind  Blows.  Under  the  pull  of  gravity 
the  atmosphere  presses  downward  and  outward, 
thus  causing  it  to  flow  from  the  several  regions  of 
great  pressure  towards  regions  of  less  pressure. 
Observe  the  arrows,  which  fly  with  the  wind,  and  it 
will  be  seen  how  generally  this  law  is  obeyed.  The 
velocity  with  which  the  wind  moves  from  the  High 
toward  the  Low  depends  on  differences  in  air  pressure, 
modified  in  the  lower  stratum  by  the  friction  offered 
in  passing  over  surfaces  of  varying  degrees  of  rough- 
ness, the  speed  being  greater  over  a  water  surface  with 
the  same  difference  in  air  pressure  than  over  a  level 
unwooded  prairie,  and  greater  over  the  open  prairie 
than  over  an  irregular  wooded  area.  To  illustrate : 

If  the  barometer  were  30.5  at  Bismark,  Dakota, 


HOW  TO  FORECAST  WEATHER      117 

and  29.5  at  Chicago,  it  would  press  upon  the  earth 
with  a  force  of  about  seventy  pounds  greater  per 
square  foot  at  the  first  place  than  at  the  second. 
This  difference  in  pressure  would  cause  the  air  to 
flow  from  Bismark  towards  Chicago  so  rapidly  that 
after  allowing  for  the  resistance  due  to  friction  on 
the  earth  there  would  remain  a  velocity  of  some 
fifty  miles  per  hour,  and  Lake  Michigan  would 
experience  a  severe  "Northwester";  and  if  the 
wind  continued  from  the  same  direction  for  twenty- 
four  hours  a  mighty  sea  would  beat  upon  the  eastern 
shore  of  the  lake,  and  mariners  and  marine  property 
would  be  at  the  mercy  of  a  destructive  tempest 
unless  the  Weather  Bureau  forecaster  were  alert 
and  gave  warning  as  soon  as  he  saw  such  a  juxtaposi- 
tion of  pressure  distribution  in  the  process  of  forma- 
tion. 

We  will  give  careful  attention  to  this  chart, 
for  when  its  details  are  understood,  others  will  be 
easily  read. 

The  chart  shows  a  winter  storm  central  in  Iowa 
on  December  15,  1893.  The  word  "Low"  marks 
the  storm  center.  It  is  the  one  place  in  all  the 
United  States  where  the  barometer  reading  is  the 
lowest.  The  heavy  black  lines,  oval  and  nearly 
concentric,  about  the  Low,  show  the  gradation  of 


118  THE  NEW  AIR  WORLD 

air  pressure  as  it  increases  quite  uniformly  in  all 
directions  from  the  center  of  the  storm  outward. 

The  arrows  fly  with  the  wind,  and,  as  will  be  seen, 
almost  without  exception  are  moving  towards  the 
Low,  or  storm  center,  clearly  demonstrating  the  effect 
of  gravity  in  causing  the  air  to  flow  from  the  several 
regions  marked  "  High  ",  where  the  air  is  abnormally 
heavy,  toward  the  Low,  where  the  air  is  lighter.  As 
the  velocity  of  water  flowing  down  an  inclined  plane 
depends  both  upon  the  slope  of  the  plane  and  the 
roughness  of  its  surface,  so  the  velocity  of  the  wind, 
as  it  flows  along  the  surface  of  the  earth  towards  the 
storm  center,  depends  on  the  amount  of  the  depres- 
sion of  the  barometer  at  the  center  and  the  resistance 
offered  by  surfaces  of  varying  degrees  of  roughness. 

Storms  and  Cold  Waves  Simply  Great  Eddies  in 
the  Atmosphere.  Now  picture  in  your  mind  that 
all  the  air  inside  the  30.2  isobar,  as  it  flows  inward, 
is  rotating  about  the  Low  in  a  direction  contrary 
to  the  movements  of  the  hands  of  a  watch,  and  you 
have  a  fair  conception  of  an  immense  atmospheric 
eddy.  Have  you  ever  watched  the  placid  waters  of 
a  deep-flowing  brook  and  observed  that  where  the 
waters  encountered  a  projecting  rock  little  eddies 
formed  and  went  spinning  down  the  stream  ?  Well, 
our  storms  are  somewhat  similar  eddies  in  the  atmos- 


-    -    •  -      '.'=:',,' 


HOW  TO  FORECAST  WEATHER      119 

phere,  more  or  less  perfect,  that  are  carried  along  by 
the  general  easterly  movement  of  the  atmosphere 
in  the  middle  latitudes  of  both  hemispheres.  But 
they  are  not  deep  eddies ;  the  Low  marks  the  center 
of  an  atmospheric  circulation  of  vast  horizontal 
extent  as  compared  with  its  thickness  or  extension 
in  a  vertical  direction.  Thus  a  storm  area  extends 
from  Washington,  D.  C.,  to  Denver,  Colorado,  and 
yet  extends  upward  only  about  six  miles.  The 
whole  disk  of  whirling  air,  six  miles  thick  and  two 
thousand  miles  in  diameter,  is  called  a  cyclone,  or 
low-pressure  area.  It  is  important  that  a  proper 
understanding  be  had  of  this  fundamental  idea, 
since  the  weather  experienced  from  day  to  day 
depends  almost  wholly  upon  the  movement  of  these 
migrating  cyclones,  or  areas  of  low  pressure,  and 
the  anti-cyclones,  or  areas  of  high  pressure. 

The  temperature  readings  are  omitted  from  each 
station,  but  the  average  temperature  of  each  quad- 
rant of  the  Low  is  shown  by  the  large  black  figures. 
The  greatest  difference  in  temperature  is  seen  to  be 
between  the  southeast  and  the  northwest  sections. 
This  is  due  in  part  to  the  fact  that  in  the  southeast 
quadrant  the  air  is  drawn  northward  from  warmer 
latitudes,  and  in  the  northwest  quadrant  it  is  drawn 
southward  from  colder  latitudes,  and  to  the  further 


120  THE  NEW  AIR  WORLD 

fact  that  winds  blowing  into  the  west  side  of  a  Low 
have  a  downward  component  of  motion,  and  those 
blowing  in  on  the  front,  or  east  side,  have  an  upward 
component. 

One  should  gain  a  clear  idea  of  the  difference  be- 
tween the  movements  of  the  air  in  the  cyclone  and 
the  movement  of  the  cyclone  itself,  or  its  translation 
from  place  to  place;  how  the  wind  must  blow  into 
the  front  of  the  storm  in  a  direction  partly  or  wholly 
contrary  to  the  movement  of  the  storm  itself,  and 
into  the  rear  of  the  storm  as  it  passes  away ;  how 
the  wind  increases  in  velocity  as  it  spirally  gyrates 
about  the  center  and  approaches  nearer  and  nearer 
the  region  where  it  must  ascend ;  how  the  higher 
layers  of  air  move  spirally  away  from  the  center  and 
thus  cause  an  accumulation  of  air  about  and  over 
the  outer  periphery  of  the  Low,  which  in  turn  presses 
downward  and  impels  the  surface  air  inward.  This 
whole  complex  system  of  motion  moves  eastward. 
Think  of  the  sun  drifting  in  space,  while  at  the  same 
time  each  of  the  planets  maintains  its  respective 
orbit,  and  it  will  help  one  to  visualize  the  phenomena 
of  a  migrating  cyclone  or  anti-cyclone. 

Chart  4,  constructed  from  observations  taken 
twelve  hours  later,  shows  that  the  Low  has  moved 
from  central  Iowa  since  8  A.M.,  and  is  now,  at  8  P.M., 


HOW  TO  FORECAST  WEATHER 

central  over  the  southern  point  of  Lake  Michigan. 
The  shaded  portion  of  the  chart  shows  that  rain 
has  fallen  during  the  past  twelve  hours  throughout 
nearly  the  entire  region  covered  by  the  cyclone. 
This  was  due  to  the  mixing  of  the  air  as  the  storm 
progressed,  to  the  cooling  by  expansion  as  the  air 
ascended,  to  the  more  rapid  rotation  about  the 
storm  center,  because  of  the  further  lowering  of  the 
barometer  at  the  center  of  the  disturbance  since  the 
preceding  chart  was  made,  and  especially  to  the 
more  humid  air  encountered  as  the  storm  moved 
eastward  and  came  nearer  to  the  supply  of  moist 
winds,  —  the  Atlantic  Ocean. 

On  Chart  5  a  line  of  arrows  extends  from  the 
storm  center  westward  to  Wyoming,  where  the 
storm  originated.  A  small  cross  inclosed  by  a  circle 
marks  its  western  extremity.  Another  cross  located 
near  Cheyenne  shows  where  the  storm  center  was 
located  twelve  hours  after  its  origin.  A  third  cross 
gives  it  location  near  Des  Moines  twenty -four  hours 
after  it  started  eastward.  It  was  here  that  we  began 
the  study  of  this  storm  on  Chart  3.  A  cross  near 
Chicago  indicates  the  distance  traveled  by  the 
center  during  the  third  twelve  hours,  and  Chart  5 
shows  its  progress  during  the  fourth  twelve-hour 
period.  When  the  storm  was  central  at  Cheyenne 


THE  NEW  AIR  WORLD 

the  danger  warnings  for  mariners  were  displayed  at 
all  ports  of  the  Great  Lakes,  as  the  forecaster  knew 
that  in  accordance  with  general  laws  the  storm  must 
move  toward  the  east.  When  it  was  centered  at 
Chicago,  danger  warnings  were  displayed  on  the 
Atlantic  coast  from  North  Carolina  to  Maine,  as 
it  was  known  that  long  before  the  storm  reached  the 
ocean  the  in-rush  of  wind  toward  the  storm  center 
would  cause  a  dangerous  on-shore  gale  and  the  break- 
ing of  heavy  seas  on  the  shore  line.  All  craft  that 
could  be  reached  with  the  danger  signals  made  safe 
in  port,  except  the  great  ocean  liners,  which  are  of 
such  strength  as  to  safely  withstand  almost  any 
storm.  A  special  set  of  observations  ordered  by 
the  Washington  office  of  the  Weather  Bureau  from 
its  stations  in  the  region  of  the  storm,  and  well  in 
advance  of  it,  kept  the  chief  forecaster  informed  as 
to  the  progress  of  the  cyclone,  and  before  the  storm 
center  reached  the  coast  the  danger  signals  com- 
municated to  mariners  the  fact  that  the  winds  would 
soon  shift  to  northwest  as  the  center  of  the  dis- 
turbance passed  out  to  sea. 

The  reader's  attention  will  now  be  directed  to 
the  red  lines  on  Chart  5 ;  they  pass  through  places 
having  the  same  temperature,  but  for  simplicity  the 
readings  of  temperature,  whereby  these  lines  were 


HOW  TO  FORECAST  WEATHER      123 

located,  are  omitted  from  the  printed  chart.  Ob- 
serve the  line  marked  40° ;  it  passes  across  southern 
New  England  to  western  New  York,  but  when  it 
reaches  the  center  of  the  storm  it  encounters  the 
cold  northwest  winds  blowing  into  the  storm  on  its 
west  side  and  is  forced  southward  to  Texas. 

Charts  3,  4,  and  5  give  a  graphic  history  of  one 
severe  winter  storm.  In  summer  such  general 
storms  do  not  often  occur.  They  are  frequent  in 
spring  and  fall,  but  of  higher  temperature  and  less 
severity  than  in  winter.  In  summer  Lows  drift 
sluggishly  across  the  continent;  the  barometer  at 
the  center  of  the  cyclone  is  usually  not  more  than 
two  to  four  tenths  of  an  inch  below  the  pressure  of 
the  Highs,  and  the  rain,  instead  of  falling  in  a  broad 
sheet,  as  shown  by  the  shading  of  charts  4  and  5, 
falls  in  numerous  sporadic  outbursts,  each  of  which 
is  but  a  few  square  miles  in  area,  their  combined 
surfaces  usually  covering  only  a  part  of  the  region 
over  which  passes  the  Low. 

Cold  Waves  and  the  Speed  of  Storm  Movement. 
Highs  and  Lows  drift  across  the  continent  from  the 
west  towards  the  east  at  the  average  rate  of  about 
six  hundred  miles  per  day,  or  about  thirty-seven 
miles  per  hour  in  winter  and  twenty-two  miles  in 
summer,  the  first  at  about  the  rate  of  an  express 


124  THE  NEW  AIR  WORLD 

train,  and  the  second  approximating  the  speed  of  a 
freight.  The  Highs  are  attended  by  dry,  cool,  and 
settled  weather.  By  a  vortical  action  at  their 
centers  they  draw  down  the  cold  air  from  great 
altitudes  above  the  clouds.  In  winter,  when  vor- 
tical action  is  vigorous,  they  may  reach  upward  to 
an  altitude  of  seven  miles.  Air  starting  downward 
from  this  region  has  a  temperature  of  some  70° 
below  zero.  We  know  this  from  the  records  se- 
cured by  sending  aloft  free  balloons  carrying  auto- 
matic thermometers.  (Chapters  II  and  III.)  This 
air  heats  by  compression  because  in  its  downward 
movement  it  is  continually  leaving  more  and  more 
air  above  it  to  exercise  pressure  upon  it.  It  gains 
about  twenty  degrees  with  each  mile  of  descent,  and 
if  there  were  no  other  factors  to  the  problem  it 
would  be  hot  air  when  it  reached  the  surface  of  the 
earth  instead  of  cold  air.  But  early  in  its  descent 
it  gains  such  heat  as  to  melt  and  evaporate  the  ice 
spiculae  floating  at  the  height  of  the  fleecy  cirrus 
clouds ;  then  it  evaporates  and  clears  away  the  moist 
clouds  lower  down  and  finally  creates  such  diather- 
mancy (the  capacity  to  transmit  heat  without  absorp- 
tion ;  see  Chapter  V)  that  the  heat  lost  by  radiation 
to  a  clear  sky  causes  what  we  call  a  "  cold  wave  ", 
and  this  notwithstanding  the  heat  of  compression. 


HOW  TO  FORECAST  WEATHER      125 

The  forecaster  first  observes  a  cold  wave  in  the 
northern  Rocky  Mountain  region,  in  the  form  of  an 
intense  High.  It  will  travel  southeastward  to  the 
center  of  the  continent,  and  often  to  the  Gulf  if  it 
is  preceded  by  an  active  Low  that  is  located  on  a 
low  latitude,  as  the  latter  will  draw  southward  the 
frosty  air  of  the  High ;  after  that  the  course  of  the 
storm  will  be  more  nearly  eastward.  Now  it  is  of  rare 
occurrence  that  a  cold  wave  gains  entrance  to  any  con- 
siderable area  of  our  territory  without  warning,  but 
in  the  early  days  of  the  Weather  Bureau  they  too 
often  reach  Iowa,  or  States  farther  east,  without  any 
notice  whatever.  It  was  then  discovered  that  a 
certain  type  of  weather  map  preceded  such  failures 
of  the  forecaster.  One  who  is  interested  in  gaining 
early  knowledge  of  the  approach  of  a  cold  wave  to 
the  United  States  should  watch  not  only  for  the 
appearance  of  abnormally  high  barometer  readings, 
from  the  stations  of  the  Canadian  Northwest,  or 
from  Montana  and  North  Dakota,  but  especially 
for  a  crescent-shaped  Low,  with  one  horn  of  the 
crescent  touching  Lake  Superior  and  the  other  ex- 
tending into  the  middle  Rocky  Mountain  region, 
at  about  Colorado.  This  Low  will  appear  to  be  an 
innocent  affair;  there  may  be  a  small  secondary 
Low  in  each  end  of  the  crescent,  and  no  High  of 


126  THE  NEW  AIR  WORLD 

any  importance  in  the  northwest,  for  which  one 
ordinarily  would  look  in  anticipating  a  cold  wave. 
But  when  this  crescent-shaped  Low  appears  on  the 
morning  weather  map,  a  High  of  marked  intensity 
invariably  will  develop  with  great  suddenness  over 
Montana  and  North  Dakota  and  bring  a  cold  wave 
to  the  Middle  Mississippi  Valley  before  the  next 
morning,  if  the  time  of  year  be  winter. 

Do  not  forget  that  the  Low  is  as  important  as 
the  High  in  causing  a  cold  wave,  for  the  High  that 
brings  the  cold  air  must  follow  in  the  track  of  the 
Low  and  will  be  attracted  by  the  latter  in  proportion 
to  its  lowness,  as  indicated  by  the  isobar  in- 
closing the  center  of  the  Low.  A  cold  wave  will 
reach  the  Gulf  only  if  the  preceding  Low  originate 
in  Texas ;  it  will  be  confined  to  the  Ohio  Valley  as 
the  limit  of  its  southern  influence  if  the  preceding  Low 
originate  in  Colorado;  and  it  will  only  skirt  the 
northern  border  of  the  United  States  and  the  Lake 
region  if  the  Low  begin  in  Montana. 

More  and  more  is  man  applying  science  to  com- 
merce and  industry.  When  the  weather  map, 
which  was  unknown  but  little  more  than  half  a 
century  ago,  indicates  the  formation  of  a  heavy 
body  of  cold  air  in  the  extreme  northwest,  the  chief 
official  forecaster  at  Washington  is  on  the  alert; 


HOW  TO  FORECAST  WEATHER      127 


he  orders  special  observations  every  few  hours  from 
the  Weather  Bureau  stations  directly  within  and 
well  in  advance  of  the  cold  area,  and  as  soon  as  he 
becomes  satisfied  that  a  cold  wave  is  on  its  way, 
the  previously  arranged  system  of  disseminating 
warnings  is  brought  into  action,  and  by  telegraph, 


CHART  6.  —  COLD  WAVE  ZONES,  MARCH  TO  NOVEMBER.    AMOUNT  OF 
FALL  AND  VERIFYING  LIMIT. 

telephone,  flags,  whistles,  bulletins,  and  other  agen- 
cies, the  people  in  every  city,  town  and  hamlet, 
and  many  in  the  stock  and  farming  regions,  are 
notified  of  the  advancing  cold  twelve  to  twenty- 
four  hours  before  it  reaches  them. 

Charts  6  and  7  show  how  the  Weather  Bureau 
defines  a  cold  wave.  There  must  be  a  fall  of  six- 
teen degrees,  eighteen  degrees,  or  twenty  degrees 


128  THE  NEW  AIR  WORLD 

within  thirty-six  hours  and  a  certain  degree  of  cold- 
ness must  be  reached.  The  charts  show  that  what 
is  a  cold  wave  in  the  Gulf  region  is  far  from  one  in 
the  northwest. 

Chart  8  shows  the  lowest  temperatures  experi- 
enced in  the  United  States  since  the  founding  of  the 


CHART  7.  —  COLD  WAVE  ZONES,  DECEMBER,  JANUARY,  AND  FEBRUARY. 
AMOUNT  OF  FALL  AND  VERIFYING  LIMIT. 

Weather  Bureau,  1871  to  1913.  Note  the  influ- 
ence of  the  Pacific  Ocean  in  forcing  the  zero  line 
from  Arizona  northward  to  British  Columbia. 

Chart  9  shows  the  number  of  times  that  a  cold 
wave  occurred  at  each  station  of  the  Weather  Bureau 
for  a  period  of  ten  years.  The  number  is  greater 
for  northern  New  England  than  for  the  Red  River 

V 


HOW  TO  FORECAST  WEATHER      129 

of  the  North  Valley,  because  practically  all  the  cold 
waves  that  cross  Minnesota  reach  New  England  ; 
and  the  latter  also  receives  fierce  boreal  visitors  that 
come  to  it  from  the  Hudson  Bay  region  lying  di- 
rectly northeast,  which  do  not  visit  any  portion  of 
Minnesota  or  the  region  farther  west.  During  the 
period  not  a  single  technical  cold  wave  occurred  at 
the  coast  stations  of  California,  Oregon,  or  Washing- 
ton, while  Red  Bluff  and  Sacramento  were  the  only 
two  places  in  California  west  of  the  Sierras,  and 
Roseburg,  Oregon,  the  only  station  west  of  the 
Cascade  Range  that  had  any,  the  numbers  being 
one,  two,  and  five  respectively.  In  the  Florida 
peninsula  south  of  Jacksonville,  Tampa  had  two, 
while  none  occurred  at  Miami.  Sometimes  the 
temperature  falls  lower  than  that  required  for  a 
cold  wave,  but  not  within  the  period  of  twenty -four 
hours  required  by  the  regulations.  A  notable  case 
in  point  is  the  severe  cold  wave  in  California  in 
January,  1913,  the  lowest  temperature  ever  observed 
being  recorded  at  San  Diego  on  the  7th,  when  the 
minimum  fell  to  25°. 

Cold  Waves  Tempered  by  Great  Lakes.  The 
severity  of  cold  waves  is  markedly  modified  by  the 
Great  Lakes,  especially  in  the  fall  and  the  first  part 
of  winter,  before  much  of  the  water  surface  is  covered 


130  THE  NEW  AIR  WORLD 

with  ice  and  snow.  Not  only  is  the  number  of  cold 
waves  much  less  at  stations  of  the  Lakes  than  at 
near-by  places  in  the  interior,  but  there  is  a  marked 
variation  in  the  number  that  occur  at  the  Lake 
stations,  depending  upon  which  side  of  the  lake  and 
how  close  to  the  water  the  station  is  located.  The 
most  striking  differences  are  noted  in  the  Lake 
Michigan  region,  the  number  on  the  west  shore  be- 
ing five  or  six  times  as  great  as  on  the  east  side. 
Milwaukee  shows  a  count  of  forty-seven  as  com- 
pared with  nine  at  Grand  Haven.  This  lake  in- 
fluence affects  the  entire  Lower  Michigan  peninsula, 
but  it  is  not  so  great  in  the  interior  and  eastern 
sections  as  along  the  west  shore,  Grand  Haven's 
nine  standing  out  against  fourteen,  fifteen,  and 
twenty-three  for  Grand  Rapids,  Detroit,  and  Port 
Huron.  A  similar  condition  is  noted  in  New  York 
State ;  Buffalo,  Rochester,  and  Oswego,  near  the  lake 
shore,  had  twenty,  twenty-seven,  and  twenty-nine 
cold  waves  respectively,  while  the  interior  stations 
of  Ithaca,  Binghamton,  and  Syracuse  had  thirty- 
eight,  forty-five,  and  fifty-two. 

Cold  Waves  Tempered  by  the  Heat  of  Cities. 
Another  reason  for  the  lack  of  uniformity  in  the  re- 
corded number  of  cold  waves  in  the  various  sections 
of  the  country  is  the  difference  between  city  and 


HOW  TO  FORECAST  WEATHER      131 

suburban  temperatures.  Stations  located  in  small 
villages  or  in  the  open  land  will  show  a  greater 
number  of  recorded  cold  waves  than  those  located 
in  large  cities,  where  the  heat  stored  up  by  pave- 
ments and  brick  buildings  during  sunshine  each 
day,  and  where  the  heat  from  thousand  of  chimneys, 
and  maybe  millions  of  human  beings,  holds  the  min- 
imum temperature  of  night  much  above  that  of  the 
free  air  in  the  open  country.  Charles  City,  where 
the  instruments  have  open  country  exposure  had 
sixty-five  cold  waves,  which  far  exceeds  the  number 
recorded  at  any  other  station  in  Iowa. 

No  matter  how  severe  may  be  the  cold  wave 
that  appears  in  the  northwest,  it  will  not  extend 
over  Wyoming,  Colorado,  Utah,  and  any  region  south 
of  them,  unless  the  center  of  the  High  extends  well 
over  the  Rocky  Mountain  Divide.  Otherwise  it 
will  come  down  the  east  slope  of  the  mountains 
and  the  cold  will  not  cross  them. 

In  the  Lows  the  conditions  of  the  air  and  its  move- 
ments are  exactly  the  reverse  of  what  they  are  in  the 
Highs ;  the  air  is  warmer  and  moister,  it  is  drawn 
spirally  inward  from  all  directions  instead  of  being 
forced  outward  as  in  the  High,  and  it  ascends  as  it 
approaches  the  center  of  depression,  sometimes 
causing  rain  or  snow  as  it  cools  by  expansion  during 


132  THE  NEW  AIR  WORLD 

its  ascent.  While  the  air  cools  with  ascent  in  the 
Low  at  the  same  rate  that  it  warms  with  descent  in 
the  High,  the  earth  experiences  a  general  warming 
effect  with  the  passage  of  the  Lows,  because  the  air 
falls  but  little  in  temperature  as  it  rises  before  it 
reaches  its  dew  point,  and  then  there  is  a  liberation 
of  the  latent  heat  of  condensation  (see  Chapter  V) ; 
and  what  is  more  important,  there  is  formed  a  cover- 
ing ofj  clouds  that  checks  or  wholly  stops  radiation 
outward  from  the  lower  air.  However  there  are 
times  when  the  passage  of  Lows  produces  a  cool- 
ing effect.  This  is  when  abnormally  hot  weather 
has  prevailed  for  some  days ;  then  the  air  may  be 
mixed,  washed,  and  cooled  by  thunder  showers. 

Highs  and  Lows  alternately  drift  across  the  conti- 
nent in  periods  of  about  three  days  each.  They 
are  a  part  of  the  divine  economy  that  provides  for 
the  seedtime  and  the  harvest,  for,  as  previously 
stated,  the  Lows  draw  the  warm,  vapor-bearing 
currents  inland  from  the  Gulf  and  the  ocean  and 
cause  them  to  deposit  their  moisture  far  to  the  north 
and  west.  Four  sevenths  of  all  our  storms  come  from 
the  middle  or  the  north  plateau  regions  of  the  Rocky 
Mountains,  or  at  least  enter  our  field  of  observation 
from  those  regions,  and  pass  from  this  arid  or  sub- 
arid  section  of  the  continent  easterly  over  the  Lakes 


HOW  TO  FORECAST  WEATHER      133 

and  New  England,  producing  but  little  rainfall. 
The  greater  part  of  the  remaining  three  sevenths 
are  first  observed  in  the  arid  regions  of  our  south- 
western States;  they  always  move  northeastward 
and  can  be  depended  on  to  give  bountiful  rainfall  so 
soon  as  or  a  little  before  they  reach  the  Mississippi 
River.  Some  of  them  cross  the  Atlantic  and  af- 
fect the  continent  of  Europe.  Charts  10  and  11  show 
the  courses  of  storms  in  this  country,  and  where 
they  originate,  or  are  first  brought  under  the  survey 
of  our  system  of  observation. 

West  Indian  Hurricanes.  A  few  of  the  most 
severe  storms  that  touch  any  portion  of  our  conti- 
nent originate  in  the  West  Indies  and  travel  in  a 
northwesterly  direction  until  they  touch  our  Gulf 
or  South  Atlantic  coast,  when,  passing  from  the  in- 
fluence of  the  northeast  trade  winds  which  carried 
them  westward,  they  recurve  and  pass  along  our 
eastern  coast,  usually  with  their  centers  offshore  and 
following  the  Gulf  Stream.  These  violent  atmos- 
pheric convulsions  are  usually  detected  in  the  pro- 
cess of  formation  through  the  effectiveness  of  the 
storm-warning  service  established  by  the  writer 
during  the  Spanish-American  War,  under  the  di- 
rection of  the  President,  for  the  purpose  of  giving 
warning  to  our  fleet  before  the  coming  of  a  hurricane. 


134  THE  NEW  AIR  WORLD 

The  President  realized  the  great  part  played  by 
storms  in  many  of  the  naval  battles  of  the  past,  and 
it  may  be  surmised  that  he  was  more  afraid  of  a 
West  Indian  hurricane  than  he  was  of  the  Spanish 
Navy.  But  Cervera  was  beaten  and  the  blockade 
was  raised  before  the  hurricanes  of  1898  began. 

Galveston  Hurricane.  The  new  Weather  Service, 
with  a  cordon  of  stations  down  the  Windward  Is- 
lands and  along  the  north  coast  of  South  America, 
surrounding  our  fleet,  and  inaugurated  as  a  war 
measure,  so  demonstrated  its  value  in  locating  and 
giving  warning  of  the  coming  of  a  hurricane  soon  after 
the  end  of  the  war  that  Congress  continued  it  as  a 
permanent  instrument  of  peace;  and  when  the  de- 
structive Galveston  Hurricane  occurred  in  1900  it 
detected  the  storm  at  its  inception  and  so  fully 
advised  shipping  of  the  storm's  movements  that 
not  a  vessel  was  lost  as  the  storm  roared  and  gyrated 
across  the  Gulf  of  Mexico  and  crashed  upon  the 
Texas  coast,  destroying  a  large  part  of  the  city 
and  drowning  six  thousand  people. 

The  hurricane  is  simply  a  rapidly  gyrating  cyclone ; 
it  usually  is  only  one  to  three  hundred  miles  in  di- 
ameter. The  storm  that  destroyed  Galveston  moved 
across  the  Caribbean  Sea  at  the  rate  of  only  about 
eight  to  ten  miles  an  hour.  It  increased  its  rate  as 


HOW  TO  FORECAST  WEATHER      135 

it  moved  northward,  crossing  the  Gulf  at  about 
fifteen  miles  per  hour.  The  speed  of  translation 
was  so  slow  and  the  velocity  of  gyration  so  rapid 
that  immense  swells  were  propagated  outward  from 
the  center  of  the  storm;  they  reached  the  Texas 
coast  some  sixteen  hours  before  the  storm  itself 
reached  Galveston.  As  it  moved  northward  to 
Iowa  its  velocity  of  translation  increased  and  its 
rate  of  gyration  decreased,  so  that  it  crossed  the 
Lakes  with  both  movements  at  about  sixty  miles 
per  hour.  At  Galveston  the  anemometer  blew  to 
pieces  after  recording  one  hundred  and  thirty  miles 
per  hour. 

Danger  to  Atlantic  Coast  Summer  Resorts.  The 
writer  frequently  has  been  asked  as  to  the  possibil- 
ities of  a  populous  Atlantic  coast  resort  being  sub- 
merged by  the  waters  driven  inshore  by  a  hurricane, 
or  being  lifted  up  in  the  center  of  the  storm  as  the 
result  of  decreased  air  pressure  inside  the  cyclonic 
whirl.  The  answer  is  that  such  a  catastrophe  is 
possible  to  any  Atlantic  coast  city  (more  especially 
those  south  of  Norfolk)  that  is  not  protected  by  a 
heavy  breakwater  of  ten  to  twenty  feet  above  sea 
level,  and  whose  building  foundations  and  walls  are 
not  of  brick  or  concrete  for  at  least  ten  feet  above 
the  water  level.  It  would  be  necessary  for  a  West 


136  THE  NEW  AIR  WORLD 

Indian  hurricane  of  unusual  intensity  —  one  similar 
to  that  which  wrecked  Galveston  —  to  be  consider- 
ably deflected  westward  out  of  its  normal  track  in 
order  to  hit  one  of  our  coast  cities  north  of  Ches- 
apeake Bay  so  that  the  center  of  the  storm  would 
pass  over  it,  or  near  enough  to  cause  destruction. 
In  Galveston  there  was  little  damage  to  strongly 
constructed  buildings  of  brick  or  stone. 

The  Breaking  of  Droughts.  It  is  most  important 
for  the  forecaster  to  know  when  and  how  droughts 
may  be  broken.  He  will  observe  that  when  the 
great  cereal  plains  are  famishing  for  moisture  the 
Lows  all  originate  on  the  middle  or  north  Rocky 
Mountain  plateau,  in  the  region  of  Colorado  or  Mon- 
tana, and  that  the  drought  continues  until  the  Lows 
begin  to  form  in  the  extreme  southwest  —  in  Arizona, 
New  Mexico,  or  Texas.  As  previously  stated  such 
Lows  always  bring  rain  as  they  move  northeastward. 

Warm  Waves.  There  come  in  summer  periods 
of  almost  stagnation  in  the  drift  of  the  Highs  and 
the  Lows  across  the  continent.  At  such  times  if  a 
High  be  centered  in  the  South  Atlantic  Ocean,  with 
its  center  at  Bermuda,  and  its  western  limits  ex- 
tending into  the  South  Atlantic  coast  States,  there 
will  result  what  is  popularly  known  as  a  warm  wave, 
for  the  air  will  slowly  and  steadily  move  from  the 


HOW  TO  FORECAST  WEATHER      137 

southeast,  where  the  pressure  is  greater,  towards 
the  northwest,  where  it  is  less;  it  will  receive  con- 
stant accretions  of  heat  from  the  radiating  surface 
of  the  earth,  and  finally  attain  to  a  temperature  that 
is  extremely  uncomfortable  to  all  forms  of  life,  that 
lowers  the  physical  stamina,  and  that  largely  in- 
creases the  death  rate.  This  superheated  condition 
of  the  lower  stratum  of  air  in  which  we  live  continues 
until  a  Low  develops  in  the  southwest  and  a  High 
in  the  northwest,  which  relation,  as  we  already  know, 
soon  brings  rainfall  to  the  interior  of  the  country. 

V-shaped  Lows  are  reasonably  sure  to  cause  pre- 
cipitation, and  if  the  barometer  at  the  center  of  the 
Low  be  five  to  seven  tenths  below  the  outer  limits 
of  the  depression,  heavy  precipitation  and  destructive 
local  storms  may  be  expected. 

Thunderstorms.  The  thunderstorm  is  caused  by 
cold  and  heavy  air  from  above  breaking  through 
into  a  lighter  and  superheated  stratum  next  the 
earth.  Some  of  them  have  a  horizontal  rolling 
motion  which  throws  forward  the  cool  air  in  the 
direction  in  which  the  storm  is  moving.  It  seldom 
is  more  than  five  or  ten  miles  in  width  and  twenty 
to  thirty  miles  in  length.  In  general,  thunderstorms 
move  from  the  west  toward  some  eastern  point,  more 
often  southwest  to  northeast. 


138  THE  NEW  AIR  WORLD 

The  frequency  of  thunderstorms  is  the  greatest 
with  ill-defined  Lows  whose  pressure  is  but  little 
below  the  normal  air  pressure  of  thirty  inches.  Any 
depression  of  the  barometer  slightly  below  the 
level  at  surrounding  stations  —  such  as  occurs  when 
a  weak  High  of  only  thirty  inches,  or  thirty  and 
one  tenth  inches,  breaks  up  into  two  or  more  areas, 
with  slightly  lower  pressure  between  them  —  is 
fruitful  of  thunderstorms.  A  High  of  but  modest 
intensity  advancing  eastward  into  a  region  of  slightly 
lower  pressure  and  much  higher  temperature  causes 
thunderstorms  along  its  eastern  front.  A  tempera- 
ture of  80°  on  the  morning  weather  map,  with  a  high 
humidity,  seldom  can  endure  beyond  the  second  day 
without  a  break  and  the  coming  of  cooling  thunder- 
showers.  Any  Low  with  abnormal  heat  and  humid- 
ity in  its  southeast  quadrant  is  usually  attended 
with  numerous  thunder  squalls  in  the  regions  of 
high  temperature  and  moisture. 

Of  the  thunderstorm  days  in  the  United  States 
few  occur  in  the  Rocky  Mountain  regions  or  in 
northern  New  England.  The  greatest  number  is 
in  Florida  and  the  Gulf  States  and  thence  north- 
ward up  the  Mississippi  Valley. 

The  Moon  Has  No  Influence  on  the  Weather. 
The  moon  used  to  be  the  farmer's  most  valued 


HOW  TO  FORECAST  WEATHER      139 

friend  as  a  forecaster  of  the  weather  and  as  a  guide 
in  the  planting  of  crops,  but  a  higher  order  of  intel- 
ligence is  causing  this  fallacy  to  pass  away.  The 
moon's  nearness  to  the  earth  and  the  fact  that  its 
phases  occur  hi  about  seven  days,  which  is  about  twice 
the  period  of  storm  recurrence,  in  the  minds  of  many 
have  endowed  it  with  potency  in  the  influencing 
of  our  weather.  Rain  may  occur  on  the  same  day 
of  the  week  for  several  weeks  in  succession,  but 
only  occasionally,  while  the  moon  is  constantly 
progressing  from  one  phase  to  another.  The  few 
cases  that  prove  the  mistaken  theory  are  taken  as 
proof  conclusive,  while  the  many  cases  that  do  not 
prove  acceptable  to  the  moon  forecaster  are  ignored 
and  not  mentioned  to  his  friends  nor  even  acknowl- 
edged to  himself.  One  is  reluctant  to  have  a  belief 
disproved,  no  matter  how  ridiculous  it  may  be.  In 
fact,  the  more  untenable  it  is,  the  more  tenaciously 
some  adhere  to  it,  as  though  they  were  loyally  stand- 
ing by  an  old  friend  who  had  made  mistakes,  but 
who  still  was  good  at  heart.  The  attraction  of  the 
moon,  because  of  its  nearness  and  notwithstanding 
its  small  mass,  is  far  more  potent  in  the  raising  of 
the  tides  of  the  ocean  than  is  the  sun,  but  its  at- 
traction on  our  atmosphere  produces  a  tide  of  only 
four  thousandths  of  an  inch  of  the  barometer,  an 


140  THE  NEW  AIR  WORLD 

influence  that  is  shadowy  and  without  the  least 
influence  in  causing  storms,  or  changes  of  any  kind  in 
the  weather ;  and  there  is  no  possible  way  in  which 
the  moon  could  influence  the  germination  of  seed 
or  the  growing  of  crops. 

Equinoctial  Storm.  As  the  summer  wanes  the 
Lows  become  more  pronounced  and  the  sporadic 
showers  give  place  to  general  rain  storms  along  in 
September.  There  is  no  objection  to  these  storms 
being  known  as  "  Equinoctial  ",  except  that  any 
date  in  the  latter  half  of  September  is  as  liable  to 
show  a  beginning  of  these  storms  as  is  the  21st  or  the 
22d.  The  equinox  simply  marks  the  middle  period  in 
the  transition  from  one  type  of  weather  to  another. 

Forecasting  from  Halos.  The  halos  that  some- 
times surround  the  sun  or  the  moon  indicate  the 
coming  of  precipitation  to  the  extent  of  making 
manifest  the  presence  in  the  upper  air  of  large  quan- 
tities of  vapor  of  water  in  a  congealed  state.  When 
the  vapor  of  water  cools  quietly  in  the  laboratory  it 
frequently  forms  minute  spheres  of  water,  which, 
strange  to  relate,  may  remain  liquid  all  the  way 
down  to  zero  and  below;  but  if  touched  or  jostled 
they  instantly  turn  to  ice,  in  the  form  of  spiculse, 
or  needles ;  they  are  simply  hexagonal  slender 
prisms  capped  by  hexagonal  pyramids.  These 


HOW  TO  FORECAST  WEATHER      141 

needles  rotate  or  spin  about  as  they  fall.  The 
geometrical  relations  of  the  facets  of  the  crystals 
to  the  axis  of  rotation  and  to  the  line  along  which 
they  fall  are  a  complex  problem  in  optics.  Suffice 
to  say  that  the  observer,  looking  through  a  filmy 
cloud  of  such  crystals,  would  see  in  one  part  of  the 
sky  a  halo,  in  another  part  an  arc  of  light,  and  in 
other  directions  bright  spots  like  the  sun,  all  of 
them  arranged  symmetrically  with  regard  to  the 
sun  and  the  observer's  zenith.  A  lunar  halo  is  a 
large  ring  concentric  about  the  moon.  A  second- 
ary halo  surrounds  the  first.  Mock  suns  or  mock 
moons  may  appear  coincident  with  solar  or  lunar 
halos.  The  ice  prisms  through  which  one  sees  the 
phenomena  both  refract  and  diffract  the  light  as 
it  passes  through  the  cloud  and  by  partly  decom- 
posing the  rays  render  visible  a  part  of  their  ele- 
mentary colors.  The  red  is  on  the  inside,  next  to 
which  is  a  little  yellow  or  green,  with  bluish  white 
on  the  outside.  In  coronas,  which  are  much  smaller, 
the  red  is  on  the  outside.  A  detailed  description  of 
these  phenomena  may  be  found  in  Moore's  "  De- 
scriptive Meteorology  "  (Appleton). 

Tornadoes.  The  cyclone  has  a  diameter  of  a 
thousand  to  two  thousand  miles,  the  hurricane  about 
one  to  three  hundred  and  the  tornado  only  one  to 


142  THE  NEW  AIR  WORLD 

ten  hundred  feet.  The  hurricane  is  much  more 
destructive  than  the  cyclone,  and  the  tornado  is 
incomparably  greater  in  velocity  of  gyration  and 
rending  force  than  the  hurricane.  New  England, 
Florida,  and  the  wide  region  including  the  eastern 
slope  of  the  Rocky  Mountains  westward  to  the 
Pacific  are  nearly  free  from  the  atmospheric  convul- 
sions that  cause  the  tornadoes,  and  they  are  infrequent 
in  any  Atlantic  coast  State,  but  numerous  in  the 
States  bordering  on  the  Mississippi  River,  and  in 
the  eastern  halves  of  Oklahoma,  Kansas,  and  Ne- 
braska. During  a  year  of  great  frequency  of  torna- 
does, about  ninety  storms  occurred,  while  during 
some  other  years  the  number  has  been  as  low  as 
twenty.  The  direction  generally  is  toward  the  north- 
east. The  average  rate  of  movement  of  the 
tornado  cloud  is  about  twenty-five  miles  per  hour 
and  the  width  of  its  destructive  path  only  five  hun- 
dred to  one  thousand  feet ;  the  time  of  passage  is  less 
than  half  a  minute.  It  does  not  come  upon  one 
unseen  and  unheralded.  Many  times  the  advanc- 
ing funnel-shaped  clouds  may  be  seen,  and  they 
always  are  accompanied  by  a  great  roar  which  may 
be  heard  for  miles.  Except  a  tornado  cellar,  the 
cellar  of  a  frame  house  is  the  safest  place.  The 
writer  has  examined  either  the  wrecks  or  the  records 


HOW  TO  FORECAST  WEATHER      143 

of  hundreds  of  tornadoes  and  does  not  know  of  a 
single  case  of  a  person  being  killed  by  a  tornado  in  the 
cellar  of  a  frame  house.  If  one  is  in  the  open  and 
a  tornado  approaches,  never  flee  to  the  north  or 
to  the  east,  but  rather  to  the  northwest,  and  one 
needs  to  travel  but  a  short  distance  to  pass  out  of 
the  track  of  the  monster.  The  tornado  always 
twists  counter  clockwise,  the  same  as  the  cyclone 
in  whose  southeast  quadrant  it  nearly  always  occurs. 
On  the  southeast  side  of  the  path  there  are  indrafts ; 
so  that  it  is  safer,  unless  the  track  of  the  oncoming 
storm  is  clearly  seen  to  be  well  to  the  north  of  the 
observer,  for  one  to  run  toward  the  northwest. 
Persons  have  stood  near  to  the  north  side  of  a  tor- 
nado track  during  its  passage  without  suffering 
injury.  If  a  cave,  the  cellar  of  a  frame  house,  or  a 
narrow  ditch  cannot  be  reached,  the  best  thing  to  do 
is  to  lie  flat  on  the  ground  as  far  from  buildings  and 
trees  as  possible. 

The  tornado  is  essentially  an  American  storm, 
doubtless  caused  by  the  running  together,  in  the 
southeast  quadrant  of  a  cyclone,  of  cold  northwest 
currents  and  warm  winds  from  the  southeast,  at  a 
time  when  the  latter  are  saturated  with  moisture. 
They  are  confined  almost  entirely  to  the  region 
between  the  two  great  mountain  systems  of  the 


144  THE  NEW  AIR  WORLD 

continent,  none  occurring  in  the  Rocky  Mountains 
and  but  few  east  of  the  Alleghanies.  The  north- 
and-south  trend  of  our  mountain  systems,  quite 
different  from  the  systems  of  Europe  and  Asia, 
facilitates  the  coming  together  of  conflicting  winds 
of  widely  different  temperatures  in  the  lower  reaches 
of  the  atmosphere  where  there  is  an  abundance  of 
water  vapor ;  no  tornadic  whirls  probably  can  occur 
without  an  abundance  of  water  vapor  and  the 
energizing  effect  of  the  heat  liberated  in  the  whirl- 
ing cloud  as  this  vapor  is  suddenly  carried  aloft  and 
liberated  by  condensation  right  in  the  center  of  the 
disturbance.  Because  of  the  relation  of  the  trend 
of  its  great  mountain  systems  to  its  oceans,  the 
United  States  occupies  a  somewhat  unique  position 
meteorologically  in  the  world.  Its  atmospheric 
conditions  are  more  active  than  those  of  any  other 
continent,  which  conditions  are  beneficial  to  the 
people  of  this  country. 

When  to  Watch  the  Weather  Map  for  Tornadoes. 
The  four  conditions  essential  to  the  formation  of 
tornadoes  are  as  follows : 

1.  A  cyclone,  the  center  of  which  is  to  the  north 
or  northwest ; 

2.  An  isotherm  of  70°  or  over  extending  from 
the   southeast  well  up  into  the  center  of  the  cy- 


HOW  TO  FORECAST  WEATHER      145 

clone,  and  then  passing  outward  toward  the  south- 
west, all  inside  the  southeast  quadrant  of  the  Low ; 

3.  Excessive  humidity; 

4.  Time  of  year  March  15  to  June  15. 

If  any  one  of  the  four  foregoing  conditions  be 
absent,  tornadoes  are  not  liable  to  occur.  The 
reason  why  spring  and  early  summer  is  the  time  when 
tornadoes  are  most  frequent  is  because  the  earth 
and  a  thin  stratum  of  air  immediately  next  the  earth 
are  heated  up  rapidly  with  the  gaining  heat  of  the 
sun's  rays  in  the  spring,  while  the  air  a  short  distance 
aloft  still  retains  much  of  the  cold  of  winter.  At  this 
time  cyclonic  action  may  bring  together  air  masses 
of  widely  different  temperatures,  especially  when 
the  upper  layers  on  the  west  side  of  the  Low  are 
drawn  down  and  commingled  with  the  hot  and 
humid  surface  winds  of  the  southeast  quadrant. 

Tornadoes  Not  Increasing.  The  writer  does  not 
indorse  the  theory  that  the  number  of  these  storms 
is  increasing;  that  the  breaking  of  the  virgin  soil 
of  the  prairie,  the  planting  or  the  cutting  away  of  the 
forests,  the  drainage  of  land  surfaces  by  tiles,  the 
stringing  of  thousands  of  miles  of  wire,  or  the  laying 
of  iron  and  steel  rails  have  materially  altered  the 
climate  or  contributed  to  the  frequency  or  the 
intensity  of  storms.  To  be  sure,  as  population 


146  THE  NEW  AIR  WORLD 

becomes  more  dense  greater  destruction  will  ensue 
with  the  same  number  of  storms. 

Difficult  to  Forecast  Tornadoes.  It  is  not  pos- 
sible for  the  forecaster  to  warn  the  exact  cities 
and  towns  that  will  be  struck  by  tornadoes  with- 
out unduly  alarming  many  places  that  will  wholly 
escape  injury.  What  we  know  is  that  tornadoes 
are  almost  wholly  confined  to  the  southeast  quadrant 
of  a  cyclone,  and  that  when  the  thermal,  hygro- 
metric,  and  time  conditions  are  favorable,  a  region 
about  one  or  two  hundred  miles  square  will  be  sacri- 
ficed by  a  number  of  these  atmospheric  twisters.  One 
of  the  most  destructive  tornadoes  of  record  dev- 
astated St.  Louis  in  the  afternoon  of  May  27,  1896. 
The  abnormal  heat  and  humidity  of  a  rather  small 
and  weak  cyclone  centered  in  eastern  Kansas  on  the 
morning  weather  map  of  that  day,  caused  the 
Weather  Bureau  to  distribute  tornado  forecasts  at 
10  A.M.  throughout  all  of  Missouri.  The  schools 
of  St.  Louis  were  dismissed  and  the  children  sent 
home  on  receipt  of  the  warning,  and  although  some 
eight  or  ten  separate  tornadoes  touched  various 
parts  of  the  State  and  the  people  were  prepared  for 
their  coming,  so  many  people  were  terrorized  by  the 
warning  in  communities  that  were  not  harmed,  that 
the  writer,  then  Chief  of  the  Weather  Bureau,  at 


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HOW  TO  FORECAST  WEATHER      147 

once  issued  orders  forbidding  the  specific  fore- 
casting of  tornadoes  in  the  future.  Under  tornadic 
conditions  the  forecast  is  for  "  conditions  favorable 
for  severe  local  storms." 

Freaks  of  the  Tornado.  The  writer  was  in  St. 
Louis  the  day  after  the  storm  and  spent  much  time 
in  examining  the  wreckage.  He  was  impressed  with 
the  fact  that  some  buildings  were  burst  outward 
and  that  all  four  walls  fell  away  from  their  bases, 
indicating  that  the  tornado  cloud  must  have  lifted 
and  dropped  down  over  them  in  such  a  way  that 
the  partial  vacuum  that  is  created  by  the  rotating 
cloud  through  centrifugal  force  so  reduced  the  pres- 
sure of  the  air  on  the  outside  of  the  houses  that  the 
normal  pressure  of  fifteen  pounds  per  square  inch 
exploded  them.  He  saw  bricks  in  a  plastered  wall 
that  were  neatly  cleaned  of  all  plaster  by  the  ex- 
pansion of  the  air  inside  the  brick,  as  the  air  pres- 
sure from  the  outside  was  reduced.  He  saw  a  two 
by  four  pine  scantling  shot  through  five  eighths  of 
solid  iron  on  the  Eads  Bridge,  the  pine  stick  pro- 
truding several  feet  through  the  iron  side  of  the  road- 
way, exemplifying  the  old  principle  of  shooting  a 
candle  through  a  board.  He  saw  a  six  by  eight 
piece  of  timber  driven  four  feet  almost  straight 
down  into  the  hard  compact  soil,  a  gardener's  spade 


148  THE  NEW  AIR  WORLD 

shot  six  inches  into  the  tough  body  of  a  tree,  a  chip 
driven  through  the  limb  of  a  tree,  and  wheat  straws 
forced  into  the  body  of  a  tree  to  the  depth  of  over 
half  an  inch.  Such  was  the  fearful  velocity  of  the 
wind  as  it  gyrated  about  the  small  center  of  the 
tornado,  —  a  velocity  exceeding  that  of  any  rifle 
bullet.  (See  Figures  17,  18,  19,  and  20.) 

Some  have  advocated  the  planting  of  trees  to  the 
southwest  of  cities  in  the  regions  where  tornadoes 
are  frequent,  so  that  the  tornadoes  may  expend  their 
energy  in  uprooting  the  trees  before  they  come  to  the 
city,  but  this  storm  traveled  through  several  miles 
of  brick  buildings,  razing  them  to  the  ground  and 
almost  pulverizing  them  and  still  left  the  city  ap- 
parently with  greater  force  than  it  had  on  entering. 
The  largest  trees  would  offer  no  more  resistance  to 
a  tornado  cloud  than  would  so  many  blades  of  grass. 

When  the  official  forecasts  contain  the  statement 
that  conditions  are  favorable  for  "  severe  local 
storms  "  it  would  be  well  to  carefully  observe  the 
formation  of  portentous  clouds  in  the  west  and 
southwest,  between  3  and  6  o'clock  in  the  after- 
noon, and  if  one  with  black,  ragged  fringes  on  its 
lower  edge  and  accompanied  with  a  noise  like  several 
railroad  trains  makes  its  appearance,  seek  safety 
in  the  cellar  of  a  frame  house. 


FIG.  20.  —  THE  ST.   Louis  TORNADO  DROVE  STRAWS  ONE  HALF 
INCH  INTO  WOOD. 


HOW  TO  FORECAST  WEATHER      149 

General  Rules  for  Forecastings.  What  has  gone 
before  in  this  chapter  gives  an  idea  of  what  guides 
the  weather  forecaster  in  making  his  deductions. 
In  brief,  he  studies  the  developments  and  the  move- 
ments of  the  Highs  and  the  Lows  during  the  past 
two  or  three  days,  as  shown  by  preceding  weather 
maps,  and  from  the  knowledge  gained  forecasts 
the  future  course  and  intensity  of  the  fair  and  the 
foul  weather  areas  for  one,  two,  or  three  days  in  ad- 
vance. By  preserving  the  weather  map  each  day 
and  noting  the  movements  of  the  Highs  and  the 
Lows,  any  intelligent  person  can  make  a  fairly 
accurate  forecast  for  himself,  always  remembering 
that  the  Lows,  as  they  drift  towards  him,  will  bring 
warmer  weather  and  sometimes  rain  or  snow,  and 
that  as  they  pass  his  place  of  observation  the  Highs 
following  in  the  tracks  of  the  Lows  will  bring  cooler 
and  fair-weather,  except  during  periods  of  extreme 
summer  heat,  when  the  Lows  bring  showers  that 
cool  the  parched  earth;  and  except  in  the  north 
Rocky  Mountain  plateau,  where  most  of  the  pre- 
cipitation occurs  after  the  center  of  the  Low  has 
passed  and  northwest  winds  are  blowing. 

The  amateur  weather  forecaster  can  closely  antic- 
ipate the  temperature  of  his  region  by  remembering 
that  the  weather  will  be  cool  and  the  humidity 


150  THE  NEW  AIR  WORLD 

low  so  long  as  the  center  of  the  predominating  High 
(the  High  inclosing  the  greatest  area  within  the 
thirty-inch  isobar)  is  north  of  his  latitude,  either 
northeast  or  northwest,  and  that  it  will  be  warm  so 
long  as  the  High  is  south  of  the  parallel  of  latitude 
that  passes  through  his  section  of  country. 

He  will  find  that  the  centers  of  the  Lows  will 
follow  closely  the  direction  indicated  by  the  isotherms 
that  lead  eastward  out  of  their  centers,  and  that  they 
move  across  the  country  from  the  west  in  quite 
regular  succession,  and  that  the  frequent  changes 
from  sunshine  to  clouds  and  from  warm  to  cold  are 
the  result  of  the  mixing  of  the  air  by  these  atmos- 
pheric eddies. 

Experience  will  teach  him  that  Lows  from  the 
southwest  are  reasonably  sure  of  causing  precipi- 
tation, and  that  if  his  temperature  be  sufficiently 
low  —  anywhere  from  zero  to  20°  —  the  fall  will 
be  in  the  shape  of  snow;  that  Lows  that  only  skirt 
our  northern  border  will  be  deficient  in  precipitation, 
even  if  they  cause  any  at  all ;  that  the  slow  settling  of 
a  High  over  the  South  Atlantic  States  means  heat 
for  all  the  rest  of  the  country  east  of  the  Rocky 
Mountains  in  degree  that  will  be  dependent  upon 
the  magnitude  and  the  intensity  of  the  southern 
High;  that  the  heat  will  continue,  even  if  tern- 


HOW  TO  FORECAST  WEATHER      151 

porarily  interrupted  by  showers,  so  long  as  this 
High  retains  its  location  in  the  southeast;  that 
tornadoes  occur  in  the  spring  of  the  year  when 
Lows  have  excessive  heat  and  humidity  in  their 
southeast  quadrants;  that  V-shaped  Lows  cause 
violent  local  storms,  if  not  tornadoes,  and  often 
deluges  of  rain ;  and  that  frosts  may  be  expected 
in  the  country  when  a  minimum  temperature  of 
40°  is  forecast  for  the  city;  and  that  the  severity 
of  cold  waves  modifies  as  they  come  eastward, 
and  that  they  will  only  flow  as  far  south  as  the  area 
covered  by  the  Low  that  preceded  them,  —  that 
is  to  say,  by  that  part  of  the  Low  included  in  the 
thirty-inch  isobar,  or  by  a  close  approximation  to 
such  area. 

National  Forecaster  E.  H.  Bowie,  known  to  the 
writer  as  one  of  the  ablest  forecasters  ever  developed 
by  the  Weather  Bureau,  in  a  recent  most  valuable 
publication  by  the  Bureau,  entitled  "  Weather 
Forecasting  in  the  United  States  ",  formulates  rules 
for  forecasting  as  follows : 

1.  When  there  is  an  area  of  high  pressure  over 
the  southeast  and  a  cold  wave  in  the  northwest 
threatens,  there  will  be  a  storm  development  in  the 
southwest  and  precipitation  will  be  general. 

2.  If  a  storm  form  in  the  southwest  and  be  forced 


THE  NEW  AIR  WORLD 

to  the  left  of  a  normal  track  (Charts  10  and  11),  an- 
other storm  will  immediately  begin  to  develop  in  the 
southwest  and  it  becomes  a  sure  rain  producer. 
Storms  that  develop  in  the  southwest  and  move 
normally  are  quickly  followed  by  clearing  weather. 

3.  Troughs    of    low    pressure  moving  from  the 
west  are  of  two  types  —  the  narrow  and  the  wide. 
The  former  moves  eastward  slowly  and  storm  centers 
develop  in  the  extreme  northern  and  the  extreme 
southern    ends.     When    the    trough    is    wide,    the 
development  of  an  extensive  storm  area  is  not  un- 
common,  especially   if   the   wide   intervening   area 
between  the  Highs  shows  relatively  high  tempera- 
tures. 

4.  When   the  northern   end  of   a  trough  moves 
eastward  faster  than  the  southern  end,  the  weather 
conditions  in  the  south  and  southwest  remain  un- 
settled and  the  chances  are  that  a  storm  will  form 
southwest    of    the   High    that  follows.     When  the 
southern  end  moves  faster  than  the  northern  end, 
settled  weather  follows. 

5.  Storms  that  start  in  the  northwest  and  move 
southeastward  do  not  gather  great  intensity  until 
they  begin  to  recurve  to  the  northward.     At  the 
time  of  recurving  they  move  slowly,  as  a  rule,  and 
care  must  be  exercised  in  predicting  clearing  weather. 


HOW  TO  FORECAST  WEATHER      153 

6.  Marked  changes  in  temperature  in  the  south- 
east and  northwest   quadrants   imply   an   increase 
in  the  storm's  intensity.     Small  temperature  changes 
do  not  indicate  a  further  development  of  the  storm. 

7.  Abnormally  high  temperatures  northwest  of 
a  storm  indicate  that  it  will  either  retrograde  or 
remain  stationary. 

8.  East  of  the  Rocky  Mountains,  a  storm  which 
moves  to  the  left  of  its  normal  track  increases  in 
intensity. 

9.  Storms  with  isobars  closely  crowded  on  the 
west  and  northwest  generally  move  slowly  and  to  the 
east  or  southeast,  and  the  precipitation  and  high 
winds  are  maintained  unusually  long  in  the  northern 
and  western  quadrants. 

10.  Storms  with  the  isobars  closely  crowded  in 
the  south  and  southeast  quadrants  move  rapidly 
northeastward  and  the  weather  quickly  clears  after 
the  passage  of  the  storm  center. 

Rules  for  Making  Local  Forecasts.  As  an  il- 
lustration of  what  may  be  done  by  the  local  observer 
or  the  layman  in  formulating  rules  of  weather  fore- 
casting for  his  immediate  vicinities,  the  following 
rules,  which  were  evolved  by  the  writer  in  1892, 
while  serving  as  the  Weather  Bureau  local  forecaster 
for  Milwaukee,  Wisconsin,  are  subjoined : 


154  THE  NEW  AIR  WORLD 

1.  In  summer  warmer  weather  occurs  after  the 
center  of  the  Low  has  passed  a  little  to  the  east, 
and  southwest  winds  are  blowing,  because  the  easterly 
winds,  which  otherwise  would  be  the  warmest  winds, 
are  cooled  by  passing  over  the  lake. 

2.  A  Low  from  the  northwest  that  reaches  western 
Minnesota  and  western  Iowa  without  precipitation 
or  clouds  will  pass  over  Wisconsin  as  a  dry  Low, 
unless  the  isobars  are  closer  than  five  eighths  of  an 
inch. 

3.  Light  frosts  will  occur  on  clear,  quiet  nights 
in  the  cranberry  marshes  when  minimum  tempera- 
tures at  Duluth  and  La  Crosse  fall  to  40°  and  45° 
respectively.     When  these  stations  record  five  de- 
grees lower  the  frost  will  be  killing  in  the  cranberry 
marshes  and  light  in  the  tobacco  fields  of  the  southern 
counties  of  the  State. 

4.  No  frost  will  occur  in  the  counties  bordering 
on  Lake  Michigan  until  the  temperatures  at  the 
Weather  Bureau  stations  fall  close  to  the  freezing 
point,  such  is  the  influence  of  the  lake  in  storing  up 
heat  and  slowly  radiating  it  during  the  night ;  and  on 
the  eastern  side  of  the  lake  its  protecting  influence 
is  much  greater. 

5.  When  the  wind  sets  in  from  points  between 
south  and  southeast  and  the  barometer  falls  steadily, 


HOW  TO  FORECAST  WEATHER      155 

a  storm  is  approaching  from  the  west  or  northwest, 
and  its  center  will  pass  near  or  north  of  the  observer 
within  twelve  to  twenty-four  hours,  with  wind  shift- 
ing to  northwest  by  way  of  south  and  southwest. 
When  the  wind  sets  in  from  points  between  east  and 
northeast  and  the  barometer  falls  steadily,  a  storm 
is  approaching  from  the  south  or  southwest,  and  its 
center  will  pass  near  or  to  the  south  of  the  observer 
within  twelve  to  twenty -four  hours,  with  wind  shift- 
ing to  northwest  by  way  of  north.  The  rapidity  of 
the  storm's  approach  and  its  intensity  will  be  indi- 
cated by  the  rate  and  the  amount  of  the  fall  in  the 
barometer. 

Vast  Extent  of  the  Area  Brought  Under  Observa- 
tion. It  is  a  wonderful  panoramic  picture  of  at- 
mospheric conditions  which,  by  the  aid  of  the  electro- 
magnetic telegraph  and  two  hundred  simultaneously 
reporting  stations,  is  presented  to  the  eye  of  the 
forecaster.  Each  day  the  kaleidoscope  changes 
and  a  new  graphic  picture  comes  into  view.  No- 
where else  in  the  world  can  the  student  of  the  weather 
find  such  opportunities. 

Early  meteorologists  studied  only  the  storm  of 
low  levels  and  humid  airs,  where  convection  only 
needed  to  carry  the  moist  air  currents  to  but  a 
slightly  higher  elevation  before  cooling  by  expansion 


156  THE  NEW  AIR  WORLD 

would  produce  condensation  and  an  immediate 
acceleration  of  the  cyclone  by  the  liberation  of 
latent  heat  within  the  region  of  the  upward-moving 
air  in  its  central  area.  They  never  had  seen  the 
cyclones  of  the  arid  northern  Rocky  Mountain 
plateau  move  down  to  our  Great  Lakes  with  rapidly 
increasing  energy,  notwithstanding  the  fact  that 
there  had  been  little  condensation,  and  hence  no 
addition  of  the  latent  heat  that  Espy  supposed  was 
essential  to  a  continuation  of  storms. 

The  widely  differing  elevation,  topography,  tem- 
perature, and  moisture  of  the  broad  region  under 
observation  by  the  United  States  Weather  Bureau 
present  conditions  unequaled  for  the  study  of  every 
phase  of  storm  development  and  translation,  or  at 
least  such  as  may  be  comprehended  from  data  taken 
on  the  bottom  of  the  atmospheric  ocean ;  and  it  is 
but  a  matter  of  a  short  time  when  the  data  for 
extremely  high  levels  will  be  added. 

Here  we  see  summer  cyclones  formed  under  the 
intense  solar  radiation  that  beats  down  through  a 
nearly  diathermanous  atmosphere  upon  the  wastes 
of  the  Rocky  Mountain  plateaus ;  cyclones  that, 
if  they  form  in  the  northern  part  of  the  plateau 
region,  move  eastward  to  our  Lakes  and  thence 
eastward  to  the  St.  Lawrence  with  scant  rainfall; 


HOW  TO  FORECAST  WEATHER      157 

cyclones  that,  if  they  have  their  origin  farther 
south  in  the  region  of  Colorado,  move  into  the 
Ohio  Valley  and  thence  to  New  England  with  con- 
siderably more  precipitation;  and  cyclones  that,  if 
they  have  their  origin  anywhere  in  our  southwest 
States  or  Texas,  or  enter  our  region  of  observation 
from  the  South  Pacific  Ocean,  can  always  be  expected 
to  cause  general  rainfall  when  they  reach  the  Lower 
Mississippi  Valley  and  later  as  they  pass  up  through 
the  central  portions  of  the  continent. 

Here  also  one  may  view  the  great  winter  cyclones 
that  originate  in  the  Pacific  between  Hawaii  and 
the  Aleutian  Islands  and  come  under  our  vision  as 
they  successfully  surmount  the  formidable  barriers 
of  the  Rocky  Mountains  with  but  little  diminu- 
tion of  energy,  sweep  across  our  continent  with 
increasing  force  and  heavy  precipitation,  and  within 
three  days  pass  beyond  our  meteorological  horizon  at 
the  Atlantic  seaboard  only  to  be  heard  from  several 
days  later  as  boreal  ravagers  of  Northern  Europe. 

The  great  anti-cyclones  that  constitute  the  Ameri- 
can cold  waves  drift  into  our  territory  from  Canadian 
Northwest  provinces,  and  are  studied  under  rapidly 
changing  conditions  during  three  thousand  miles 
of  their  course. 

West  Indian  hurricanes,  at  sea  level  and  in  humid 


158  THE  NEW  AIR  WORLD 

air,  which  are  the  most  violent  of  all  storms  except 
the  American  tornado,  intrude  themselves  into  the 
domain  covered  by  the  weather  map  at  Florida  or 
the  East  Gulf  coast  and  usually  pass  off  to  the 
northeast  with  high  winds  skirting  our  southern 
coast  stations. 

Permanent  Highs  and  Lows  in  the  Pacific  Are 
Great  Centers  of  Action.  Near  the  end  of  Chap- 
ter XII  reference  is  made  to  the  fact  that  there  is 
a  barrier  in  the  Pacific  Ocean  that  interferes  with  the 
movement  of  storms  from  the  Orient,  but  which 
does  not  entirely  stop  their  progress.  Extensive 
Highs  and  Lows,  sometimes  called  "  Centers  of 
Action  "  because  they  do  not  migrate  like  the  travel- 
ing Highs  and  Lows  that  cause  the  alternations  of 
weather  that  we  experience  from  day  to  day,  are  also 
called  Sub -permanent  Highs  and  Lows.  They  are 
the  parent  systems  out  of  which  come  many  of  the 
Highs  and  Lows  that  cross  the  North  American 
continent,  and  they  act  as  a  bar  to  the  free  passage 
of  storms  from  the  Far  East.  As  these  Sub-per- 
manent areas  shift  their  centers  a  little  to  the  north 
or  to  the  south  they  change  the  character  and  the 
line  of  movement  of  the  storms  and  cool  waves  that 
come  to  us,  and  they  alter  the  general  character  of 
the  weather  for  thousands  of  miles  to  the  east  of 


HOW  TO  FORECAST  WEATHER      159 

them.  In  the  region  of  Iceland  is  the  center  of  an 
extensive  Sub-permanent  Low  that  has  much  to  do 
in  controlling  the  weather  of  Europe,  and  there  is 
a  Sub-permanent  High  central  at  or  near  Bermuda 
in  the  southern  part  of  the  North  Atlantic  Ocean. 
Whenever  the  latter  is  built  up  by  having  a  mi- 
grating High  from  the  North  American  continent 
join  with  it,  the  whole  United  States  experiences 
what  is  called  a  "  hot  wave",  and  the  heat  continues 
as  long  as  this  Sub-permanent  High  remains  un- 
usually high  and  extends  its  western  limits  to  in- 
clude our  South  Atlantic  States. 

The  matter  in  the  foregoing  paragraph  is  so 
important  that  it  will  be  restated  in  slightly  different 
form :  Whenever  either  the  High  or  the  Low  Center 
of  Action  (Sub-permanent  High  and  Low),  out  of 
which  comes  nearly  all  of  the  migrating  Highs  and 
Lows,  shifts  its  normal  seasonal  position,  then 
storms  are  erratic  and  unusual  weather  occurs  over 
the  North  American  continent  and  farther  eastward. 
The  reason  why  much  the  greater  number  of  the 
storms  that  cross  the  United  States,  the  Atlantic 
Ocean,  and  Europe  originate  either  in  our  Rockies, 
the  Canadian  Northwest,  or  just  off  the  Alaskan 
coast  is  due  to  the  fact  (Chart  1,  page  99)  that 
the  Low  center  of  action  is  normally  over  the  middle 


160  THE  NEW  AIR  WORLD 

and  northern  Rocky  Mountain  plateau  in  summer, 
and  over  the  Aleutian  Islands  (Chart  2,  page  100) 
in  winter.  The  High  that  follows  the  migrating 
Low  in  winter  either  separates  from  the  center  of 
action  central  over  the  Canadian  Rockies  (Chart  2), 
or  from  the  one  central  at  Honolulu;  if  from  the 
latter,  the  weather  will  be  simply  cooler  after  the 
passage  of  the  Low,  but  if  the  High  separates  from 
the  center  of  action  in  the  Canadian  Rockies  it  will 
constitute  a  cold  wave  as  it  follows  a  Low  southeast- 
ward into  the  interior  of  the  United  States  and  then 
eastward  to  the  coast. 


CHAPTER  X 
CLIMATE 

CHANGE  OF  SOLAR  RAYS  INTO  LIGHT,  HEAT,  AND  OTHER 
FORMS  OF  ENERGY  AS  THEY  ARE  ABSORBED  BY  OUR 
ATMOSPHERE  OR  AS  THEY  ENCOUNTER  THE  EARTH  — 

TEMPERATURES    OF    WATER,    EARTH,    AND    AIR HOW 

SANITARY  HOMES  MAY  BE  CHEAPLY  CONSTRUCTED 
BELOW  GROUND,  COOL  IN  SUMMER  AND  WARM  IN 
WINTER 

Difference  between  Climate  and  Weather.  One 
may  speak  of  the  weather  of  to-day  or  of  some  time 
that  is  past,  but  not  of  the  climate  of  to-day,  or  of 
any  day,  month,  or  year  that  is  gone :  for  the  climate 
of  a  place  is  determined  by  a  study  of  its  weather 
records  for  a  long  period  of  years.  Climate  changes 
so  slowly  that  we  speak  of  the  movement  as  a 
mutation  rather  than  as  a  change.  The  time  that 
has  elapsed  since  the  discovery  of  the  barometer  and 
the  thermometer  —  about  two  and  a  half  centuries 
—  is  so  short  as  to  show  little  if  any  change  in 
climate,  while  the  weather  changes  from  day  to  day. 


162  THE  NEW  AIR  WORLD 

The  Sun  Our  Only  Source  of  Appreciable  Heat. 
Each  one  of  the  stars  visible  to  the  eye  and  many 
of  the  millions  that  are  not  visible,  are  suns  accom- 
panied by  planets.  Their  conditions  are  similar 
to  those  of  our  sun,  except  that  most  of  them  are 
larger  than  our  sun,  some  a  million  times  larger. 
But  their  distance  is  so  great  that  they  exercise 
little  or  no  influence  in  the  heating  of  the  earth. 
Light  travels  at  about  the  rate  of  186,400  miles  per 
second,  and  yet  these  stars  are  so  distant  that  if  the 
nearest  one  had  been  created  at  the  time  of  the  sign- 
ing of  the  Declaration  of  Independence  we  still 
would  be  in  ignorance  of  its  existence,  for  its  first 
rays  of  light  would  not  reach  us  for  many  years  yet 
to  come;  and  light  from  some  of  the  remote  suns 
that  we  call  stars  requires  thousands  of  years  to 
come.  It  is  apparent  therefore  that  we  depend 
exclusively  upon  our  own  luminary  for  the  heat 
that  warms  our  atmosphere  and  gives  life  to  the 
surface  of  the  earth. 

Different  Temperatures  with  the  Same  Quantity 
of  Solar  Heat.  On  the  same  day  of  each  year  at 
the  same  place  practically  the  same  amount  of  heat 
falls  upon  and  into  the  earth's  atmosphere  from  the 
sun,  but  rarely  does  the  same  temperature  and 
weather  occur,  and  often  there  is  wide  variation  in 


CLIMATE 


163 


the  weather  of  the  same  day  of  two  different  years. 

The  first  of  July  may  be  cold  enough  to  wear  an 

overcoat  at  midday, 

or  the  first  of  January 

may  be  so  temperate 

as  to  permit  the  don- 

ning of  summer  habil- 

iments, while,  accord- 

ing   to   the   amount 

of  heat  received  from 

the  sun,  there  would 

have    occurred    the 

i  ,  ,.     FIG.  21.  —  Equinoxes,  March  21  and  Sep- 

USUal  Seasonal  COndl-       tember22     Axis  perpendicular  to  Sun's 


tions     On     the     days       **?*•    Day  and  night  everywhere  equal. 

named  had  there  been  no  other  influence  than  the 
direct  action  of  the  sun's  heat.  The  cause  of  these 
seeming  inconsistencies  is  due  to  the  motions  of  the 
atmosphere  in  a  stratum  only  five  to  seven  miles  in 
depth,  air  cooling  by  expansion  as  it  ascends  in  cy- 
clonic whirls  and  heating  as  it  descends  in  anti- 
cyclonic  movements.  Condensation,  in  the  form  of 
cloud  or  rain  or  snow,  also  introduces  complications, 
usually  producing  a  cooling  effect  in  summer  and  a 
warming  in  winter.  In  other  words  :  interference  in 
the  uniform  and  gradual  change  in  temperature,  of 
the  lower  stratum  of  air  in  which  we  live,  from  the  heat 


164 


THE  NEW  AIR  WORLD 


FIG.  22.  —  Summer    Solstice,    June    21. 
North  Pole  leans  towards  Sun's  rays. 


of  summer  to  the  cold 
of  winter,  and  then 
the  reverse  process,  is 
due  entirely  to  the 
heating  and  the  cool- 
ing of  the  lower  air  by 
its  upward  and  down- 
ward motions. 

If  the  earth's  axis 
were  vertical  to  the 
plane  of  its  orbit  all 

places  on  its   surface  always  would  have  days  of 

twelve  hours  each  and  the  nights  would  be  of  the 

same    length  ;      sun- 

shine   would  just 

touch    both    poles 

(Figure  21)  through- 

out the  entire  course 

of  the  earth  around 

the    sun    and    there 

would  be  no  seasons. 

One  would  need  to 

Change  One's  location 

On  the  earth  in  order 

i  t 

to  get   a  change   of 


Weather,  which  Would 


Q'  23-~  Winter  Solstice,  December  21. 
North  Pole  is  dark  now  instead  of  light, 
as  at  Summer  Solstice.  Pole  leans  in 
same  direction  but  Earth  being  on  oppo- 

site  side  of  its  orbit  rays  come  from  oppo_ 

site  direction.     Refer  to  Figure  24. 


CLIMATE 


165 


Autumn 


FIG.  24.  — Note  that  direction  of  axis  does  not  change  as  Earth  moves 
around  Sun.  This  causes  variation  in  area  of  surface  illuminated.  If 
axis  were  perpendicular  to  plane  of  orbit  there  would  be  no  seasons. 

be  monotonous  and  quite  different  from  the  active 
conditions  of  the  atmosphere  that  we  now  enjoy. 
The  whole  conditions  of  life  would  be  altered  for 


v""\ 


FIG.  25.  —  As  angle  of  incidence  decreases  from  90°  to  10°  the  heat  received 
on  upper  end  of  blocks  is  spread  over  greater  area  at  bottom,  and  its 
temperature  diminished.  (Abbe.) 

the  worse.  You  have  seen  a  top  tilt  over  to  one 
side  as  it  spun  on  the  floor.  In  the  same  way  the 
earth  spins  on  its  axis  as  it  pursues  its  course 
around  the  sun  without  changing  the  direction  to- 
wards which  its  axis  points,  as  shown  by  Figure  24. 


166  THE  NEW  AIR  WORLD 

The  intensity  of  the  sun's  rays  at  sunrise  and  at 
sunset  is  less  than  at  midday  because  the  quantity 
of  heat  received  at  the  outer  limits  of  the  atmosphere 
on  a  given  area,  as  for  instance  at  the  area  of  the 
upper  ends  of  the  blocks  in  Figure  25,  passes  through 
a  deeper  stratum  of  air  the  lower  the  angle  of  in- 
cidence, and  because  it  is  distributed  over  a  larger 
area  when  it  reaches  the  surface  of  the  earth. 

As  the  heat  of  day  increases  from  morning  until 
midday  and  then  decreases,  so  does  the  heat  of  the 
year  increase  from  midwinter  to  midsummer  and 
then  decrease,  and  for  the  same  reason:  change 
in  obliquity  of  the  sun's  rays,  to  which  must  be 
added  change  in  distance  from  the  central  luminary. 
Figure  26  shows  that  the  sun  reaches  its  greatest 
midday  altitude  on  June  21st  and  its  least  on  De- 
cember 21st. 

Solar  Rays  Absorbed  by  the  Atmosphere.  The 
atmosphere  of  the  earth  absorbs  about  seventy-six 
per  cent,  of  the  solar  rays  that  pass  through  it. 
About  one  half  is  absorbed  by  a  cloudless  atmos- 
phere, and  nearly  all  is  absorbed  or  reflected  away 
by  a  cloudy  air.  On  the  average  about  fifty-two  per 
cent,  of  the  earth's  surface  is  obscured  by  clouds 
all  the  time,  which  reduces  the  total  amount  of  heat 
that  reaches  the  earth  to  but  twenty-four  per  cent. 


CLIMATE  167 

But  in  regions  like  the  high  plateau  of  the  Rocky 
Mountains,  where  there  is  little  cloudiness  or  mois- 
ture in  the  air,  fully  fifty  per  cent,  reach  the  earth. 
At  the  equator,  when  the  sun  is  in  the  zenith  at 
noon,  the  rays  strike  the  earth  perpendicularly  and 


FIG.  26.  —  Observer  at  center  of  picture  at  latitude  45°.  Showing  altitude 
attained  by  the  Sun  at  midday  and  length  of  its  track  above  the  horizon 
at  the  Summer  and  Winter  Solstices  and  at  the  two  Equinoxes. 

reach  the  earth  through  the  shortest  air  distance 
possible ;  but  for  latitudes  far  north  or  south  of  the 
equator,  the  rays  are  more  oblique  and  must  pass 
through  an  ever-increasing  thickness  of  air  as  the 
latitude  increases.  Consequently  the  heat  that 
reaches  the  earth  at  high  latitudes  decreases,  not 
only  on  account  of  the  greater  obliquity  of  the 
sun's  rays,  but  also  because  of  the  longer  path  of 


168  THE  NEW  AIR  WORLD 

atmosphere  traversed,  which  causes  a  further  loss 
by  absorption. 

The  Lag  of  Earth  Temperatures.  The  solar 
rays  reach  their  greatest  intensity  on  June  21st, 
in  the  Northern  Hemisphere,  when  the  sun  attains 
the  farthest  point  north,  and  the  obliquity  of  its 
rays  is  the  least,  but  the  highest  temperature  of  the 
air  for  the  year  does  not  occur  on  the  average  for  a 
month  or  six  weeks  later,  due  to  the  capacity  of  the 
earth  and  air  to  absorb  heat ;  and  the  maximum  for 
the  earth  does  not  occur  until  still  later.  The  sun 
is  the  farthest  south  on  December  21st,  but  the 
minimum  air  temperature  of  the  year,  on  the  aver- 
age, does  not  occur  until  a  month  later,  and  at  a 
later  period  in  the  earth.  At  Munich,  Bavaria,  at 
a  depth  of  four  feet,  the  minimum  annual  temper- 
ature occurs  on  the  2d  of  March,  and  the  maximum 
on  the  24th  of  August.  For  each  increase  of  four 
feet  in  depth  the  time  of  occurrence  of  either  max- 
imum or  minimum  temperature  is  retarded  twenty- 
one  days,  the  minimum  not  occurring  until  the  23d 
of  May  at  a  depth  of  20.2,°  and  the  maximum  being 
retarded  until  the  17th  of  November. 

Annual  Range  in  Air  Temperature.  The  difference 
in  temperature  between  winter  and  summer  in- 
creases from  the  equator  northward  and  from  all 


CLIMATE  169 

oceans  toward  the  interior  of  continents,  and  is 
greater  in  the  middle  latitudes  on  the  eastern  side 
of  large  bodies  of  land  than  on  their  western  side. 
Yakutsk,  Siberia,  has  experienced  80°  below  zero 
in  January  and  102°  above  in  July,  making  a  range 
of  182°.  Dawson,  Canada,  has  a  record  of  68° 
below  for  winter  and  94°  above  for  summer,  making 
a  range  of  162°.  In  marked  contrast  with  these 
large  differences,  shown  in  the  northern  interior 
of  continents,  is  the  annual  range  at  Samoa,  from 
a  maximum  of  92°  to  a  minimum  of  62°,  a  range 
for  the  year  of  only  30°  for  this  island  of  the  Pacific, 
located  near  the  equator. 

Reversal  of  the  Seasons  in  the  Two  Hemispheres. 
The  summer  is  shorter  in  the  Southern  Hemisphere 
than  in  the  Northern  and  the  winter  is  longer,  but 
the  Southern  Hemisphere  is  nearer  to  the  sun  in 
the  summer  and  farther  away  in  winter,  conditions 
that  tend  to  add  to  the  extremes  of  both  seasons. 
Because  of  the  slowness  of  the  earth  in  passing 
through  one  half  of  its  orbit,  the  northern  summer 
lasts  ninety-three  days,  while  that  of  the  Southern 
Hemisphere  lasts  but  eighty-nine  days.  The  result 
is  that  during  like  seasons  and  during  the  whole  year 
the  two  hemispheres  receive  exactly  the  same  quan- 
tity of  heat. 


170  THE  NEW  AIR  WORLD 

Only  Water  Vapor  Protects  the  Earth  from  Death 
by  Freezing.  In  Chapter  IV  you  are  told  that  the 
earth  is  surrounded  by  four  atmospheres  that 
conduct  themselves  each  quite  independently  of  the 
others,  and  that  water  vapor  (aqueous  vapor)  is 
one  of  them.  Water  vapor  plays  the  most  important 
part  in  absorbing  incoming  rays  and  in  absorbing 
and  reflecting  back  outgoing  heat  rays  from  the 
earth.  Without  the  vaporous  atmosphere  the  sun's 
rays  would  be  but  slightly  absorbed  as  they  entered 
and  radiation  from  the  earth  would  readily  escape 
through  the  atmosphere  to  outer  space.  No  matter 
how  fiercely  the  sun  might  shine,  life  on  the  earth 
would  be  entirely  destroyed  by  cold. 

When  water  vapor,  clouds,  or  dust  motes  intercept 
certain  portions  of  the  sun's  rays,  they  change  them 
from  vibrations  in  ether  to  the  motions  of  molecules, 
and  the  motions  of  these  molecules  are  expressed  in 
a  rise  in  temperature  in  the  vapor,  cloud,  or  dust. 
Earth  radiations  of  heat,  having  longer  and  slower 
wave  lengths  than  those  that  come  from  the  sun, 
are  more  readily  absorbed  by  the  atmosphere. 

One  of  the  principal  functions  of  the  atmosphere 
is  to  protect  the  earth  from  the  intense  cold  of  outer 
space,  which  must  be  near  or  at  absolute  zero  — 
459°  below  the  zero  mark. 


CLIMATE  171 

Why  Should  Not  Mountain  "Peaks  Be  Warm? 
They  Are  Nearer  the  Sun.  The  absorption  by  the 
atmosphere  of  both  solar  and  terrestrial  radiation 
is  greater  in  the  lower  levels  of  the  air,  where  water 
vapor,  cloud,  and  dust  are  the  densest,  while  the 
transmission  of  both  incoming  and  outgoing  radiation 
is  more  rapid  through  the  pure  air  aloft.  Thus 
we  account  for  the  coolness  of  all  mountain  peaks, 
and  the  perpetual  freezing  temperatures  of  some, 
even  though  they  be  located  in  the  tropics,  and 
though  their  tops  occupy  positions  several  miles 
nearer  the  sun  than  the  bases  from  which  they  rise. 

How  the  Earth  Cools  at  Night.  Radiation  from 
the  earth  goes  on  day  and  night,  winter  and  sum- 
mer. During  daylight  the  gain  of  heat  is  greater 
than  the  loss,  while  at  night  the  reverse  is  true. 
After  sunset  both  the  earth  and  the  air  continue  to 
cool  by  radiation  unchecked  by  the  incoming  heat 
of  the  daytime.  The  earth  loses  heat,  even  under 
a  clear  sky,  more  freely  than  the  air,  with  the  result 
that  the  surface  of  the  ground  and  of  vegetation 
may  fall  to  a  temperature  ten  to  fifteen  degrees 
lower  than  that  of  the  air  at  a  few  hundred  feet 
elevation.  This  condition  is  called  "  temperature 
inversion."  The  greater  difference  will  occur  when 
there  is  little  wind  to  mix  the  air.  On  a  clear  night 


172  THE  NEW  AIR  WORLD 

the  radiation  outward  will  be  rapid ;  then,  if  the  wind 
be  light,  there  may  occur  an  increase  in  temperature 
up  to  a  height  of  two  hundred  to  four  hundred 
feet,  and  then  a  fall,  reaching  the  surface  temperature 
at  about  two  thousand  feet  elevation,  unless  the 
ground  be  wet,  or  the  location  be  adjacent  to  a 
considerable  body  of  water. 

A  Cloud  Covering  Cools  by  Day  and  Warms  by 
Night.  One  of  the  principal  functions  of  clouds 
is  to  conserve  the  heat  of  the  sun.  A  covering  of 
cloud,  fog,  or  dense  haze  may  not  only  screen  off 
the  heat  of  day,  but  greatly  retard  the  lowering  of 
temperature  at  night  by  reflecting  and  radiating 
back  to  the  ground  much  of  the  heat  that  it  has  lost. 

The  Temperature  of  Oceans,  Lakes,  and  Rivers. 
The  same  quantity  of  heat  falling  upon  different 
kinds  of  matter  produces  different  temperatures,  de- 
pending on  the  capacity  (specific  heat)  of  each  kind 
of  matter  to  absorb  or  hold  heat;  this  is  notably 
apparent  when  the  matter  is  land,  water,  or  air ;  for 
the  same  quantity  of  heat  will  raise  the  temperature 
of  a  water  surface  only  about  one  fourth  as  much 
as  it  will  a  land  surface.  Water  rejects  by  reflection 
a  considerable  amount  of  the  solar  rays  that  fall 
upon  it,  while  land  reflects  but  a  small  part;  and 
of  that  which  is  received  upon  the  top  layer  of  water 


CLIMATE  173 

much  is  rendered  latent  in  the  process  of  evaporation 
and  does  not  impart  warmth  to  the  water.  Solar 
rays  also  penetrate  water  to  a  considerable  depth 
and  are  quite  uniformly  absorbed  by  the  whole 
stratum  penetrated.  These  conditions  cause  large 
water  surfaces  and  the  air  immediately  over  them 
to  have  a  much  lower  temperature  during  the  day 
and  a  much  higher  temperature  during  the  night; 
and  also  lower  temperatures  during  summer  and 
higher  temperatures  during  winter,  than  occur  over 
a  land  surface  of  the  same  latitude. 

Fresh  Water  and  Salt  Water  Have  Different 
Freezing  Temperatures.  In  the  ratio  of  93.5  to 
100  the  specific  heat  of  sea  water  is  less  than  that 
of  fresh  water.  Sea  water  is  a  better  conductor 
of  heat,  so  that  it  penetrates  to  a  greater  depth 
in  salt  water  in  the  same  period  of  time  than  it 
does  in  fresh  water.  Sea  water  regularly  contracts 
with  falling  temperature  until  its  greatest  density 
occurs  at  four  degrees  below  freezing,  when  it 
becomes  solid  ice  and  expands  in  the  process  of 
freezing ;  otherwise  it  would  not  float. 

A  Wonderful  Phenomenon.  In  this  respect  a  most 
wonderful  and  unexplainable  phenomenon  occurs  with 
regard  to  fresh  water.  Not  only  sea  water  but 
practically  all  other  forms  of  matter  —  liquid,  solid, 


174  THE  NEW  AIR  WORLD 

and  gaseous  —  expand  with  increasing  heat  and 
contract  with  decreasing  heat,  except  fresh  water 
between  39°  and  32°,  which  actually  expands  with 
falling  temperature.  It  seems  as  though  the  Creator 
had  gone  over  His  work  and  made  revisions  and 
corrections  here  and  there,  for  unless  the  law  with 
regard  to  the  contraction  of  liquids  with  falling  tem- 
peratures had  been  reversed  for  fresh  water  between 
39°  and  32°  our  rivulets,  streams,  lakes,  and  rivers 
would  freeze  from  the  bottom  upward  and  the  life 
of  inland  water  be  wholly  or  partly  destroyed. 

Even  more  calamitous  would  be  the  floods  of 
springtime,  for  melting  snows  and  falling  rains 
would  spread  over  and  erode  the  cultivated  fields 
of  the  husbandman  instead  of  being  carried  away  by 
the  open  channels  of  streams,  as  is  largely  done  now. 

The  Freezing  of  Fresh  and  of  Salt  Bodies  of  Water. 
The  freezing  of  water  does  not  take  place  upon  the 
surface  of  water  only,  as  many  suppose.  Congela- 
tion takes  place  about  millions  of  minute  atoms  of 
matter  carried  by  the  water  in  suspension.  Water 
expands  in  the  process  of  freezing  and  each  particle 
of  ice,  no  matter  in  what  part  of  the  body  of  water 
it  is  formed,  immediately  rises  to  the  surface  because 
of  the  gain  in  its  buoyance  as  it  changes  from  the 
liquid  to  the  solid  form. 


CLIMATE  175 

When  the  surface  of  water  cools  by  radiation  to 
a  cooler  air  it  gains  in  specific  gravity  and  sinks 
and  warmer  water  comes  up  to  take  its  place  and 
in  turn  be  cooled  and  sink;  thus  a  circulation 
is  established  which  continues  in  fresh  water 
until  every  part  of  the  body  of  water  has  fallen 
to  39°  and  in  salt  water  to  28°.  At  these  tem- 
peratures the  two  waters  reach  their  maximum 
density.  With  the  further  cooling  of  salt  water 
particles  of  ice  form  and  rise  to  the  top,  as  already 
described.  With  the  cooling  of  fresh  water  below 
39°  the  law  that  holds  good  for  all  higher  tempera- 
tures is  reversed  and  expansion  of  volume  begins, 
which  continues  until  32°  is  reached.  Therefore, 
fresh  water  of  any  temperature  between  39°  and  32° 
may  float  upon  water  that  is  considerably  warmer; 
in  fact,  it  has  less  specific  gravity  at  32°  than  at  46°. 
At  32°  that  which  was  a  liquid  becomes  a  solid  and 
still  further  suddenly  expands  its  volume. 

The  Cold  of  Ocean  Bottoms.  Few  have  any 
idea  of  the  enormous  volume  of  cold  water  that 
lies  upon  the  surface  of  the  earth,  three  fourths  of 
which  is  covered  with  oceans  whose  depths  average 
two  miles  and  in  many  places  are  five  miles.  Below 
one  mile  in  depth  these  oceans  are  always  at  about 
the  freezing  point  of  salt  water,  which  is  28°, 


176  THE  NEW  AIR  WORLD 

except  in  the  tropics,  where  it  is  but  little  wanner, 
varying  between  34°  and  36°. 

How  Temperatures  of  Inclosed  Seas  Differ  from 
Those  of  Oceans.  We  will  take  the  Red  Sea  as 
an  example.  It  is  180  miles  wide  and  extends  in 
a  nearly  north  and  south  direction  for  1450  miles, 
about  one  half  of  it  lying  within  the  tropics.  Evap- 
oration takes  place  at  a  rapid  rate,  but  only  the 
surface  water  of  the  Indian  Ocean  on  the  south 
is  able  to  enter  to  take  the  place  of  that  which  is 
lost,  for  a  bar  or  sill  at  the  entrance,  extending 
from  the  bottom  to  within  twelve  hundred  feet  of 
the  surface,  separates  the  deep  water  of  the  sea 
from  that  of  the  outside  ocean.  Its  surface  tem- 
peratures vary  about  as  the  Indian  Ocean,  being 
85°  hi  summer  and  70°  in  winter.  Both  bodies  of 
water  decrease  in  temperature  at  about  the  same 
rate  down  to  the  level  of  the  sill,  where  the  tem- 
perature remains  constant  the  year  through  at 
70°.  Here  a  marked  difference  occurs,  for  the 
sea,  which  has  a  depth  of  7200  feet,  maintains  the 
same  temperature  of  70°  all  the  way  down  to  the 
bottom;  while  the  ocean  continues  to  decrease 
in  temperature  down  to  a  depth  of  about  six  thou- 
sand feet,  where  a  temperature  of  34°  to  36°  prevails 
throughout  the  year.  A  similar  condition  exists 


CLIMATE  177 

with  relation  to  the  Mediterranean  and  the  Atlantic 
Ocean.  At  the  top  of  the  sill,  which  is  1140  feet 
below  the  surface,  the  temperature  of  both  bodies 
is  55°,  and  this  degree  of  heat  is  maintained  all  the 
way  down  to  the  bottom  of  the  Mediterranean, 
while  in  the  Atlantic  Ocean,  at  the  same  depth  as 
the  bottom  of  the  Mediterranean,  the  temperature 
is  only  35°. 

How  the  Temperature  of  Water  Changes  with 
Latitude,  Season,  and  Depth.  It  is  impossible  to 
name  a  given  temperature  as  prevailing  over  bodies 
of  water  at  all  places  on  the  same  parallel  of  latitude, 
because  ocean  currents  soon  move  water  heated  hi 
one  latitude  to  a  higher  or  a  lower  position.  At  the 
equator  the  surface  temperature  is  between  82° 
and  84°;  it  changes  less  than  one  degree  between 
day  and  night,  and  not  over  five  degrees  between 
winter  and  summer ;  and  below  twenty-four  hundred 
feet  there  is  no  difference  between  the  seasons,  the 
daily  variation  ceasing  at  less  than  a  hundred  feet. 
Below  six  thousand  feet  the  temperature  is  always 
near  the  freezing  point  of  fresh  water. 

In  the  middle  latitudes  the  surface  variation  is 
from  50°  in  winter  to  68°  in  summer. 

At  latitude  70°  N.  the  surface  temperature  has 
but  a  small  daily  variation,  and  a  yearly  range  of 


178  THE  NEW  AIR  WORLD 

from  35°  for  winter  to  45°  for  summer;  at  a  depth 
of  twenty-four  hundred  feet  it  remains  steady 
at  32°. 

From  this  level  there  is  a  gradual  decrease  to  a 
depth  of  six  thousand  feet,  where  a  constant  tem- 
perature of  28°  exists,  and  below  this  there  is  no 
change.  The  temperature  of  Lake  Superior  decreases 
down  to  a  depth  of  two  hundred  forty  feet,  where  a 
temperature  of  39°  continues  throughout  the  year, 
as  it  does  downward  for  the  remainder  of  the  dis- 
tance to  the  bottom,  which  has  an  average  depth 
of  nine  hundred  feet. 

Direction  of  Wind  Affects  Shore  Temperature  of 
Water.  Onshore  winds  skim  off  the  warm  surface 
water  and  drive  it  shoreward,  where  it  banks  up, 
and,  pressing  downward,  causes  the  colder  water 
beneath  to  flow  back  seaward.  In  like  manner, 
offshore  winds  blow  off  the  top  water  near  the 
shore  and  send  it  out  to  sea,  and  colder  water  rises 
to  take  its  place. 

Great  Heat  of  the  Earth's  Interior.  We  are 
ignorant  of  the  conditions  of  matter  under  the 
heating  effect  of  the  enormous  pressure  that  exists 
near  the  center  of  the  earth,  but  it  is  probable  that 
pressure  prevents  it  from  changing  from  a  solid  to 
a  liquid  or  a  gaseous  form.  The  surface  of  the 


CLIMATE  179 

solid  earth  rises  to  a  much  higher  temperature  as 
the  solar  rays  fall  upon  it  than  does  a  water  surface, 
or  the  air  immediately  above,  because  it  is  a  poor  re- 
flector, a  poor  conductor,  and  a  poor  radiator,  and 
when  dry  does  not  get  any  cooling  effect  from  evap- 
oration. 5.  Solar  heat  ceases  to  be  apparent  at  a  depth 
that  varies  with  the  latitude  and  the  conditions  of 
the  soil  with  regard  to  moisture  and  specific  heat, 
but  everywhere  at  less  than  fifty  feet. 

At  the  poles  and  for  some  distance  away  the 
earth  is  covered  with  ice  or  snow  the  entire  year 
and  is  frozen  to  a  considerable  depth.  In  the 
interior  of  Siberia  and  some  parts  of  Alaska  only 
a  thin  stratum  of  soil  thaws  out  under  the  heat  of 
summer.  Beginning  at  about  fifty  feet,  there  is  an 
increase  of  temperature  downward,  but  it  is  not 
the  same  for  all  places,  varying  from  a  degree  for 
forty  feet  to  a  degree  for  one  hundred  feet.  Taking 
the  average  of  the  increase  with  depth,  water  would 
boil  at  ninety-five  hundred  feet  and  the  hardest 
rock  be  molten  at  thirty  miles.  At  a  depth  of 
3490  feet  near  Berlin,  the  temperature  was  found 
to  be  116°,  while  it  was  only  108°  at  the  same  depth 
at  Wheeling,  West  Virginia,  and  in  both  places  there 
is  no  change  from  day  to  night  or  from  winter 
to  summer. 


180  THE  NEW  AIR  WORLD 

Soil  Usually  Warmer  Than  Air  Next  Above.  In 
summer,  June  to  August,  the  bare,  dry,  top  soil 
is  warmer  than  the  air  ten  feet  above  during  all 
hours  of  the  day  and  night,  at  times  the  difference 
being  as  much  as  forty  degrees  at  midday.  During 
winter,  December  to  February,  it  is  slightly  cooler, 
except  between  9  A.M.  and  3  P.M.  when  the  ex- 
cess is  seldom  more  than  ten  degrees.  Evapora- 
tion from  a  wet  soil  lowers  its  temperature  below 
that  of  the  air  immediately  above  through  the 
rendering  latent  of  a  large  quantity  of  heat.  A 
melting  snow  surface  also  is  below  the  temperature 
of  the  air  because  of  the  heat  employed  in  changing 
the  snow  to  the  liquid  form. 

Let  Mother  Earth  Cool  and  Refresh  You  During 
the  Heat  of  Summer.  How  little  the  average  man 
realizes  the  possibilities  for  improving  his  condition 
that  lie  close  at  hand.  He  does  not  know,  or  he  is 
indifferent  to  the  fact,  that  only  three  feet  from  the 
surface  of  the  ground  it  is  as  cool  at  midday  as  at 
midnight,  and  that  there  is  no  diurnal  variation  in 
temperature  below  that  depth,  and  no  annual 
variation  below  a  depth  of  from  thirty  to  forty  feet. 
If  one  were  to  set  down  the  temperature  of  each  day, 
add  the  numbers  at  the  end  of  the  year,  and  divide 
the  sum  by  365  the  quotient  would  equal  the  tern- 


CLIMATE  181 

perature  always  found  at  that  place  at  a  depth  of 
about  thirty  feet.  The  temperature  of  a  deep- 
flowing  spring  is  always  about  the  mean  annual  air 
temperature  of  the  place.  Here  is  health-giving  cool- 
ness for  summer  and  warmth  for  winter  of  which  one 
takes  little  heed  and  derives  practically  no  profit. 

Remarkable,  is  it  not?  And  these  beneficent 
conditions  are  universal  and  available  for  all,  except 
to  those  crowded  into  congested  centers  of  popula- 
tion. The  temperature  is  54°  in  the  Mammoth 
Cave  in  Kentucky  and  shows  no  change  from  day  to 
day  and  from  winter  to  summer. 

During  the  extreme  heat  of  summer  and  the  cold 
of  winter  many  could  profitably,  healthfully,  and 
pleasantly  live  below  ground.  During  such  periods 
the  cellar  of  the  house,  which  should  be  deep  and 
spacious,  even  extending  beyond  the  dimensions  of 
the  edifice  above,  if  a  continuous  supply  of  pure  air 
could  be  forced  through  it,  or  natural  ventilation 
accomplished  by  the  plan  outlined  below,  should 
be  the  lounging,  resting,  and  sleeping  place  of  the 
occupants  of  the  household.  It  is  not  impossible 
or  extremely  difficult  to  change  the  stagnant,  moist, 
germ-laden,  ill-smelling  air  of  the  average  cellar,  in 
which  it  is  positively  dangerous  to  spend  much  time, 
into  active,  pure,  and  delightfully  healthful  air,  — 


182  THE  NEW  AIR  WORLD 

air  in  which  the  worn  and  weary  worker  from  the 
heat  of  the  farmer's  field,  or  the  artisan  and  the 
clerk  from  the  debilitating  temperatures  of  the 
factory  and  the  office  could  recuperate  from  the  toil 
of  the  day,  and  from  which  they  would  go  forth 
each  morning  invigorated  for  another  day's  efficient 
service,  instead  of  dragging  weary  limbs  from  hot, 
sleepless  beds,  each  morning  less  in  energy  than  the 
day  before.  As  is  shown  in  other  parts  of  this  book, 
the  researches  of  Huntington  have  proven  con- 
clusively that  man  is  at  his  lowest  physical  and 
mental  points  of  efficiency,  and  more  subject  to  the 
contraction  of  disease  through  weakness,  in  mid- 
summer and  midwinter,  and  that  the  hotter  the 
summer  and  the  colder  the  winter  the  less  is  his 
energy  and  the  lower  is  his  power  of  resistance. 

The  whole  problem  is  one  of  ventilation.  While 
this  is  simple,  it  must  be  scientifically  done.  The 
ideal  location  for  a  living  cellar  is  a  hillside.  It  is 
easy  to  install  ventilators  in  the  roof  of  a  cellar 
no  matter  where  located,  but  these  are  of  no  avail 
whatever  if  there  is  not  adequate  air  drainage  at 
the  bottom  of  the  cellar.  From  the  cellar  in  a 
hillside  a  conduit  can  lead  from  the  bottom  of  the 
inclosure  and  have  its  opening  at  a  lower  level,  there- 
by accomplishing  drainage  and  circulation,  which  are 


CLIMATE  183 

all-important  in  the  creating  of  a  sanitary  condition 
of  air  under  the  cool  earth.  For  each  thousand 
cubic  feet  of  cellar  space  there  should  project  from 
the  roof,  to  a  height  of  at  least  six  feet  above  ground, 
a  separate  ventilator  shaft  of  at  least  one  square 
foot  cross-section  dimension.  A  like  ventilating 
capacity  should  be  provided  from  the  bottom  out- 
ward to  a  lower  level,  but  here  two  or  more  shafts 
may  be  combined  in  one,  so  the  proper  capacity  is 
secured.  During  the  day  the  draft  will  be  upward 
through  this  system.  But  at  night,  except  when 
the  wind  is  brisk,  the  direction  of  movement  of  the 
air  is  reversed,  and  the  cool  air  of  the  minimum 
temperature  of  night  or  early  morning,  because  of 
its  greater  density,  drops  down  into  the  cellar.  The 
drainage  shaft  should  be  provided  with  a  damper, 
which  should  be  closed  in  the  early  morning,  about 
daybreak,  entrapping  the  cold  air  of  night.  The 
lower  opening  should  be  covered  with  wire  netting, 
to  exclude  small  animals,  and  the  whole  construction 
be  of  concrete,  rendering  it  imperishable  and  rat- 
proof. 

Inexpensive  but  Efficient  Cold  Storage.  Such  a 
sanitary  cellar  as  described  above  provides  an 
excellent  storage  for  fruits  and  vegetables,  com- 
paring favorably  with  the  much  more  expensive 


184  THE  NEW  AIR  WORLD 

artificial  refrigeration.  By  an  intelligent  manipu- 
lation of  the  damper  in  the  lower  shaft,  cool  storage 
may  be  provided  for  fruit  and  other  produce  in  the 
early  fall,  and  protection  secured  against  the  extreme 
cold  of  winter. 

Why  Does  Air  Cool  with  Ascent  and  Heat  with 
Descent?  If  a  mass  of  air  be  elevated  183  feet  it 
will  be  found  to  have  lost  one  degree  in  temperature, 
because  there  is  less  air  above  to  exert  pressure  upon 
it  and  it  therefore  expands  to  greater  volume,  and 
in  the  process  of  expansion  work  is  performed  which 
employs  heat  and  renders  it  latent.  One  minute, 
one  hour,  or  a  thousand  years  thereafter,  if  this 
same  air  be  lowered  to  its  former  elevation,  it  will 
be  compressed  into  its  previous  dimensions  and  the 
heat  energy  that  formerly  was  employed  to  expand 
it  will  be  restored  to  the  sensible  condition.  This 
ratio  of  183  feet  to  one  degree  does  not  hold  for 
any  extended  movement,  because,  as  soon  as  the 
dew  point  of  the  air  is  reached,  condensation  in  the 
form  of  cloud  or  rain  occurs  and  the  heat  of  con- 
densation is  released;  that  is  to  say,  the  same 
quantity  of  heat  employed  to  create  the  water 
vapor  at  some  previous  time  and  thereby  rendered 
latent  is  now  become  sensible  and  partly  makes  up 
for  the  loss  by  expansion  as  the  air  ascends.  The 


CLIMATE  185 

average  is  therefore  about  three  hundred  feet  for 
one  degree. 

Height  of  Freezing  Cold  in  the  Free  Air.  The 
frost  level  remains  constant,  winter  and  summer, 
over  the  equator  at  about  eighteen  thousand  feet. 
Elsewhere  this  level  rises  and  falls  with  the  seasons, 
the  amplitude  of  the  movement  increasing  with 
latitude  and  being  greater  over  land  than  over 
water  on  the  same  parallel. 

Daily  Range  of  Temperature  in  the  Free  Air. 
The  difference  between  the  temperature  of  day  and 
that  of  night  decreases  with  altitude  in  the  free  air 
and  ceases  at  about  eight  thousand  feet.  It  is 
greatest  during  clear  weather  and  least  in  cloudy 
weather.  Narrow  valleys  may  show  a  greater 
daily  range  than  hilltops.  When  the  sky  is  clear, 
radiation  from  the  hillsides  may  heat  the  air  in  a 
valley  to  almost  furnace  heat  at  midday,  while  at 
night  the  air,  coming  in  contact  with  cool  vegetation 
higher  up,  chills  and,  gaining  in  weight  by  con- 
traction, flows  down  and  collects  in  the  valley, 
making  the  bottom  of  the  valley  warmer  during 
day  and  colder  during  night  than  the  air  above. 
Often  moisture-laden  winds  precipitate  much  of 
their  water  vapor  as  the  air  cools  by  expansion  in 
passing  over  a  mountain  range.  These  winds 


186  THE  NEW  AIR  WORLD 

carry  a  comparatively  dry  air  over  to  the  leeward 
side  of  the  mountain,  where  the  daily  range  of 
temperature  will  be  much  greater  than  on  the 
windward  side  at  the  same  elevation.  San  Fran- 
cisco, where  the  prevailing  winds  come  from  the 
ocean,  has  a  less  range  than  New  York,  where  the 
predominating  winds  are  from  the  land;  but  New 
York  is  influenced  by  its  proximity  to  the  ocean,  for 
its  range  is  much  less  than  at  Denver,  in  the  interior 
of  the  continent.  The  range  is  less  on  the  east  side 
of  Lake  Michigan  than  on  the  west  side,  as  it  is 
with  relation  to  all  similar  bodies  of  water. 

Man  Soon  Adjusts  Himself  to  Changes  in  Al- 
titude. In  Colonial  days  it  was  noted  that  horses 
coming  down  from  the  mountains  in  North  Carolina 
ran  swifter  in  the  races  the  first  day  or  two  after 
changing  to  a  lower  level.  In  going  to  a  higher 
altitude  an  increase  in  the  number  of  red  corpuscles 
in  the  blood  enables  it  to  absorb  oxygen  more  readily, 
and  thus  compensate  for  the  loss  in  the  density  of 
the  air.  Because  of  this  gain  in  the  chemical  ac- 
tivities of  the  life  current,  one  feels  a  marked  increase 
in  strength  on  coming  to  a  lower  level,  but  the  gain 
lasts  for  only  a  short  time  before  there  is  a  read- 
justment to  former  conditions.  Persons  with  weak 
hearts  may  not  be  able  to  live  at  an  altitude  of 


CLIMATE  187 

four  thousand  feet,  and  most  people  experience  in- 
convenience, at  least,  on  first  reaching  ten  thousand 
feet;  but  nature  is  accommodating,  and  a  number 
of  large  cities  prosper  at  altitudes  of  from  one  to 
two  miles. 


CHAPTER  XI 
HOW  CLIMATE  IS  MODIFIED  AND  CONTROLLED 

IF  the  surface  of  the  earth  were  all  land,  and  the 
axis  of  the  earth's  rotation  were  perpendicular  to 
the  plane  of  the  earth's  orbit,  the  day  and  the  night 
would  be  equal  everywhere,  and  there  would  be  no 
seasons.  There  would  be  no  wind,  for  the  friction 
of  the  air  against  the  rotating  earth  would 
soon  cause  all  levels  of  the  atmosphere  to 
take  up  the  exact  easterly  velocity  of  the  solid 
body  below.  The  atmosphere  would  be  contracted 
by  cold  and  drawn  downward  so  as  to  have  less 
depth  at  the  poles  than  at  any  place  having  latitude, 
and  it  would  be  deepest  at  the  equator,  where  the 
direct  rays  of  the  sun  would  expand  it  to  an  altitude 
of  probably  twice  what  it  could  have  at  the  poles. 
Centrifugal  force  —  the  force  that  causes  mud  to 
fly  off  the  rim  of  a  swiftly  rotating  wagon  wheel  — 
would  further  lower  the  height  of  the  atmosphere 
at  the  poles  and  cause  it  still  more  to  extend  outward 


HOW  CLIMATE  IS  CONTROLLED     189 

at  the  equator.  The  atmosphere  would  soon  ad- 
just itself  to  these  constant  conditions  and  forces 
and  thereafter  remain  at  rest  relative  to  the  earth. 
There  would  be  no  life,  for  there  would  be  no 
vaporous  atmosphere  if  the  surface  all  were  without 
water.  There  would  be  extremely  little  heat  to 
disturb  the  atmosphere  with  motion,  for  the  dry 
gases  of  the  atmosphere  are  practically  diather- 
manous,  and  the  heat  of  the  sun  would  pass  out  by 
radiation  from  the  burnt  and  parched  surface  of  the 
earth  during  daytime  without  imparting  more  than 
a  minute  fraction  of  its  energy  to  the  atmosphere; 
and  at  night  the  thin  surface  of  the  top  soil  that 
had  been  heated  to  a  furnace  temperature  during 
sunshine  would  be  quickly  locked  in  the  fastnesses 
of  intense  cold  —  probably  200°  below  zero. 

If  we  now  incline  the  axis  of  our  imaginary  earth 
23£°,  we  shall  introduce  seasons  whose  only  change, 
the  one  from  the  other,  will  be  in  the  duration  of 
sunlight,  as  there  is  no  water  vapor  to  absorb  and 
utilize  the  sun's  rays  in  the  initiation  of  motion  and 
the  creation  of  storms.  We  are  assuming  that  there 
would  be  enough  heat  absorbed  to  prevent  the 
atmosphere  from  liquefying,  which  it  would  do  at 
any  temperature  lower  than  312°  below  zero.  If 
the  temperature  were  to  fall  below  the  liquefying 


190  THE  NEW  AIR  WORLD 

point  of  air,  we  would  have  the  singular  phenomenon 
of  the  air  expanding  to  a  gas  during  daylight  and  con- 
densing to  a  liquid  during  nighttime,  and,  of  course, 
that  would  mean  motion  and  winds,  but  of  such  a  na- 
ture that  one  would  hardly  dare  speculate  as  to  their 
peculiarities. 

We  introduce  these  hypothetical  cases  for  the 
purpose  of  conveying  a  clearer  idea  of  the  over- 
lapping of  conditions  and  the  combinations  of  forces 
that  influence  and  control  the  seasons,  the  climate, 
and  the  weather  of  the  earth. 

If  the  surface  of  the  earth  were  all  water  and  its 
axis  perpendicular  to  the  plane  of  its  orbit,  the  day 
and  the  night  would  everywhere  be  equal  and  there 
would  be  no  seasons.  With  a  water  surface  there 
would  be  an  atmosphere  nearly  if  not  quite  saturated 
with  vapor  of  water,  in  other  words,  of  practically  one 
hundred  per  cent,  relative  humidity.  It  is  doubtful  if 
either  animal  or  vegetable  life  could  exist;  the  first 
would  die  of  internal  heat,  because  a  saturated  air  would 
permit  of  no  cooling  by  evaporation  from  the  pores  of 
the  skin,  or  from  the  tongue  and  mouth  of  animals  that 
do  not  perspire ;  and  the  second  could  not  grow  with- 
out the  chemical  action  of  sunshine,  which  is  a  neces- 
sary part  of  the  laboratory  of  the  leaf  of  every 
growing  plant,  the  sunshine  acting  upon  the  green 


HOW  CLIMATE  IS   CONTROLLED     191 

granular  matter  which  constitutes  the  chlorophyll 
of  the  plant.  There  would  be  little  difference  be- 
tween the  temperature  of  day  and  of  night  —  prob- 
ably not  more  than  one  degree.  As  the  earth  would 
everywhere  and  at  all  times  be  covered  with  a  deep 
stratum  of  cloud  there  would  be  little  loss  of  heat 
to  space  by  radiation  and  the  temperature  would 
be  excessive,  rising  in  the  tropics  to  near  the  boiling 
point.  We  will  assume  that  the  atmosphere  would 
reach  a  stable  and  unchanged  condition  of  great 
heat  and  humidity  and  be  without  motion  or  pre- 
cipitation. 

If  now  we  incline  the  axis  of  this  water-covered 
earth  and  introduce  the  complication  of  seasons, 
we  shall  not  only  have  variation  in  the  hours  of 
sunshine,  increasing  as  we  go  from  the  equator  to- 
ward the  poles,  but,  the  capacity  of  air  for  moisture 
being  less  and  less  with  falling  temperature,  we  shall 
have  downpours  of  rain  as  the  summer  slowly  merges 
into  fall  and  the  latter  into  winter.  Although 
the  air  will  be  saturated,  there  probably  will  be 
no  rainfall  from  the  time  when  the  temperature 
begins  to  rise  after  midwinter  until  it  reaches 
and  passes  the  maximum  heat  of  summer.  It  is  fair 
to  assume  that  during  the  rainy  period  there  will  be 
cyclonic  storms  with  torrential  precipitation,  and 


192  THE  NEW  AIR  WORLD 

that  the  anti-cyclones  that  are  a  necessary  con- 
comitant of  cyclones,  while  they  may  cause  a  tempo- 
rary cessation  of  precipitation  in  the  area  that  they 
cover,  by  the  dynamic  heating  of  the  air  in  their 
downward  motions,  will  be  ineffective  in  fully  clear- 
ing away  the  clouds  from  a  water-covered  earth. 
It  is  doubtful  if  such  an  earth  would  be  suitable  for 
life,  —  certainly  not  for  man. 

The  Real  Earth  of  Land,  Water,  and  Inclined 
Axis.  The  different  manner  in  which  land  and 
water  surfaces  absorb,  radiate,  and  reflect  the  heat 
from  the  sun  has  a  profound  influence  on  climate, 
which  also  is  modified  by  latitude,  elevation  above  sea 
level,  elevation  above  a  valley  or  above  a  surround- 
ing plane,  direction  of  wind,  height  and  trend  of 
direction  of  hills  and  mountains,  the  position  of 
lakes  and  inland  seas,  the  relative  position  and 
magnitude  of  continents  and  oceans,  storm  tracks, 
and  ocean  currents. 

Influence  of  Continents  and  Oceans  on  Climate. 
Charts  1  and  2  (pages  99  and  100),  constructed  from 
observations  taken  on  ships  and  on  land,  for  a  long 
series  of  years,  show  certain  Highs  and  Lows  of 
vast  extent,  sometimes  called  "  Centers  of  Action  ", 
because  they  do  not  travel  across  continents  and 
oceans,  as  do  the  migrating  Highs  and  Lows  that 


HOW   CLIMATE  IS  CONTROLLED     193 

cause  weather.  Rather  do  they  slowly  reverse 
their  relative  positions  between  winter  and  summer. 
Continents  cool  by  radiation  in  winter  more  rapidly 
than  do  oceans ;  the  air  contracts,  settles  down  and 
grows  denser  and  air  flows  in  at  the  top  from  the 
oceans  and  outward  at  the  surface  of  the  earth 
toward  the  oceans ;  thus  is  built  up  the  winter  Highs, 
or  centers  of  action,  on  continents.  Continents 
heat  up  by  absorption  in  summer  more  rapidly  than 
do  oceans ;  the  air  expands,  rises,  and  flows  away 
in  the  upper  levels  to  oceans  and  flows  in  at  the 
bottom  from  the  oceans ;  and  thus  are  the  Lows, 
or  centers  of  action,  established  on  continents  in 
summer.  It  is  apparent  that  these  processes  must 
be  reversed  for  the  oceans,  and  that  the  Highs  will 
be  found  there  in  the  summer  and  the  Lows  in  the 
winter.  Carefully  follow  the  illustrations  of  these 
principles  by  examining  the  whole  region  north  of 
the  equator  on  Charts  1  and  2. 

In  the  Southern  Hemisphere  there  is  not  such  a 
pronounced  shifting  of  the  Highs  and  the  Lows  from 
oceans  to  continents  and  back  again,  with  change  in 
the  seasons,  as  there  is  in  the  Northern  Hemisphere, 
because  of  the  small  area  of  land  in  comparison  with 
that  of  water;  but  in  the  midst  of  the  southern 
summer,  which  occurs  in  January  (Chart  2),  Lows 


194  THE  NEW  AIR  WORLD 

are  shown  over  South  America,  Africa,  and  Australia. 
Note  how  the  winds  blow  out  of  all  the  Highs  and 
into  all  the  Lows.  Also  observe  that  the  winds 
generally  blow  from  about  latitude  30°  north  and 
south  towards  the  equator,  due  to  the  great  heat 
of  the  tropics,  which  causes  the  air  to  rise  and  in 
the  high  levels  to  flow  northward  and  southward, 
settling  down  to  the  earth  again  through  the  belts 
of  high  pressure  that  irregularly  encircle  the  earth 
at  latitudes  30°  north  and  south. 

In  the  interior  of  continents  the  temperature 
falls  lower  at  night  and  rises  higher  during  the  day, 
and  falls  lower  in  winter  and  rises  higher  in  summer 
than  on  any  of  their  coasts.  On  the  coast  of  central 
California,  for  instance,  the  ocean  is  so  cool  in  summer 
and  the  winds  blow  so  steadily  from  it  that  the 
thermometer  ranges  between  55°  and  70°,  even  when 
there  are  temperatures  of  over  100°  but  a  few  hundred 
miles  away  in  the  great  interior  valleys,  or  on  the 
broad  plateaus  of  the  mountains.  New  York  and 
Boston,  in  nearly  the  same  latitude,  also  have  their 
summer  temperatures  modified  by  ocean  influence, 
but  they  are  on  the  east  side  of  a  broad  continent, 
where  the  prevailing  westerly  winds  give  to  them 
more  the  character  of  a  continental  climate  than 
one  marine;  but  occasionally  the  east  wind,  for  a 


•• 


HOW  CLIMATE  IS  CONTROLLED     195 

short  time,  gives  to  them  the  modifying  influence 
of  the  ocean.  In  the  winter  the  influence  of  the 
oceans  is  to  modify  the  extremes  of  cold,  the  same 
as  they  do  the  excessive  heat  of  summer. 

Chart  8  (page  129)  showing  the  lowest  tempera- 
tures ever  recorded  at  Weather  Bureau  stations,  and 
Chart  12,  presenting  the  average  of  the  highest  daily 
temperatures  of  July,  graphically  show,  clearer 
than  any  text  can  describe,  the  influence  of  conti- 
nents and  oceans  on  climate.  On  the  Atlantic  the 
average  maximum  of  day  varies  from  70°  on  the 
Maine  coast  to  85°  on  the  coast  of  North  Carolina; 
while  on  the  Pacific,  where  the  marine  influence  is 
stronger,  the  average  is  from  65°  on  the  Washington 
coast  to  80°  on  the  coast  of  southern  California. 
But  near  the  center  of  the  United  States  where  the 
continental  influence  predominates,  the  average  of 
the  highest  daily  temperatures  varies  from  85°  to 
90°.  On  Chart  8,  showing  the  lowest  temperatures, 
the  line  of  20°  below  zero  passes  through  Boston, 
southwest  to  Chattanooga,  west  to  Flagstaff,  Arizona, 
and  then  irregularly  north  to  Seattle,  showing  the 
influence  of  both  oceans  in  carrying  the  line  north- 
ward. 

Because  of  the  vast  extent  of  the  Eurasian  (Europe 
and  Asia)  continent  the  difference  between  conti- 


196  THE  NEW  AIR  WORLD 

nental  and  marine  climates  is  more  marked  than  in 
the  Western  Hemisphere.  Huntington  and  Gushing, 
in  their  splendid  work  on  "  Principles  of  Human 
Geography",1  make  a  comparison  between  the  south- 
ern Lofoten  Islands,  off  the  coast  of  Norway,  and 
Verkhoyansk  in  Siberia,  which  probably  furnish  the 
greatest  contrast  to  be  found  anywhere  between 
places  of  the  same  latitude.  Although  both  are 
inside  the  Arctic  Circle,  the  influence  of  the  Atlantic 
Ocean  with  its  warm-water  currents  coming  all  the 
way  from  the  tropics  (Chart  13)  protects  the  Lofoten 
Islands  from  the  extreme  cold  that  otherwise  would 
come  to  them ;  vegetation  remains  green  and  cattle 
are  pastured  every  month  in  the  year.  But  the 
ocean  retains  nearly  the  same  temperature  in  sum- 
mer as  in  winter,  and  as  a  result  the  Islands  are 
too  cold  to  grow  trees  or  many  crops.  Verkhoyansk 
is  so  different  that  one  can  scarcely  believe  that 
both  places  are  in  the  same  latitude.  At  the  Si- 
berian town  the  winter  temperature  falls  to  70°  or 
80°  below  zero  every  winter,  and  has  been  known  to 
register  90°  below  zero.  It  is  said  that  steel  skates 
often  will  not  "  take  hold  "  but  slip  sideways  as 
well  as  forward  on  the  surface  of  the  excessively  cold 
ice.  This  doubtless  is  due  to  the  fact  that  under 

1  John  WUey  &  Sons,  New  York. 


HOW  CLIMATE  IS   CONTROLLED    197 

ordinary  winter  cold  the  weight  of  the  skater  melts 
a  thin  film  of  water  under  the  edge  of  the  skate, 
which  freezes  instantly  when  the  skate  passes  and 
relieves  the  pressure.  But  here  the  cold  is  so  in- 
tense that  the  weight  of  no  skater  is  sufficient  to 
lubricate  his  movements  with  water  molecules. 
Remarkable  to  relate,  the  summer  at  Verkhoyansk 
is  warmer  than  in  the  islands  off  the  Norwegian  coast, 
due  to  the  rapidity  with  which  the  land  surface  warms 
up  under  the  action  of  the  solar  rays  in  the  midst 
of  a  continental  area  remote  from  water,  75°  to  80° 
frequently  being  recorded  during  the  long  summer 
days.  The  ground  never  thaws  for  more  than  a 
foot  or  so,  but  a  number  of  crops  are  successfully 
grown. 

In  the  interior  of  a  continent  like  that  of  Siberia 
or  of  North  America  not  only  the  changes  from 
season  to  season  but  from  day  to  night  are  extreme ; 
while  in  mid-ocean  the  diurnal  and  the  annual  range 
of  temperature  is  small,  day  and  night,  winter  and 
summer  being  much  the  same.  A  place  is  influenced 
by  the  ocean  in  proportion  to  its  distance  from  the 
sea,  the  presence  or  the  absence  of  hills  or  mountains 
between  the  place  and  the  water,  and  by  the  fact 
that  the  prevailing  winds  come  from  or  go  to  the 
ocean.  Cities  as  far  inland  as  Baltimore  and  Phila- 


198  THE  NEW  AIR  WORLD 

delphia  have  their  extremes  of  temperature  some- 
what modified  by  the  Atlantic  Ocean,  and  if  it  were 
not  for  the  Coastal  and  the  Sierra  Nevada  Mountains 
the  influence  of  the  Pacific  Ocean  would  be  felt  at 
least  as  far  inland  as  Denver,  and  the  great  Rocky 
Mountain  plateau  would  be  one  of  the  garden  plots 
of  the  world.  The  influence  of  the  Pacific  would 
reach  inland  farther  than  now  does  the  Atlantic 
because  of  the  prevailing  westward  drift  of  the 
atmosphere  in  all  middle  latitudes. 

Exaggeration  of  the  Forest  Influence  on  Climate. 
Chapter  XIII,  on  Change  of  Climate,  shows  more 
in  detail  the  process  whereby  the  sun  lifts  up  the 
water  vapor  from  the  Gulf  of  Mexico  and  the  At- 
lantic Ocean  and  how  cyclonic  storms  draw  this 
vaporous  atmosphere  northwestward  far  into  the 
interior  of  the  continent,  the  Alleghany  Mountains 
not  being  high  enough  to  offer  serious  obstruction. 

The  writer  would  again  caution  the  reader  not 
to  be  misled  by  any  pseudoscientist,  no  matter 
how  worthy  his  purpose  may  be,  ^ho  would  teach 
that  the  operations  of  men  in  changing  forest  areas 
to  cultivated  fields,  gardens,  villages,  and  cities,  has 
in  the  slightest  degree  harmfully  affected  the  climate, 
or  augmented  floods  or  intensified  droughts.  A 
field  of  grass,  of  wheat,  of  corn;  an  orchard  of 


HOW  CLIMATE  IS  CONTROLLED     199 

fruit;  a  highway  bordered  with  towering,  majestic 
oaks  and  elms ;  or  a  grove  of  cultivated  trees  about  a 
prosperous  home  is  just  as  beneficial  to  the  climate  as 
the  thickest  and  most  impenetrable  forest  and  far 
more  pleasing  to  the  eye  and  helpful  to  mankind. 
Forests  should  be  protected,  conserved,  and  grown 
because  we  need  timber,  not  because  a  lot  of  foolish 
people  are  writing  nonsense  about  them. 

Influence  of  Lakes  and  Rivers.  With  the  ex- 
ception of  contributing  to  the  formation  of  occasional 
fogs  over  their  surfaces  and  the  adjacent  low  lands, 
through  the  rising  of  warm  water  vapor  into  the 
cold  air  that  often  collects  at  the  bottom  of  valleys 
during  nighttime,  rivers  exercise  little  influence 
on  climate.  Lakes  exert  a  modifying  influence  on 
the  temperature  of  places  near  their  shores  but 
only  for  a  few  miles  therefrom,  and  they  are  too 
small  to  exert  any  appreciable  influence  on  rainfall. 
If  one  examine  charts  showing  the  average  rain- 
fall for  the  United  States  by  seasons,  he  will 
observe  that  the  amount  gradually  shades  off  as 
the  distance  from  the  Gulf  or  Ocean  increases, 
without  any  relation  whatever  to  the  five  Great 
Lakes.  Deserts  exist  on  either  side  of  the  Caspian 
Sea,  although  it  slightly  increases  the  rain  of  the 
Elburz  Mountains  to  the  south.  If  these  great 


200  THE  NEW  AIR  WORLD 

bodies  of  water  do  not  influence  the  rainfall,  how 
ridiculous  to  assume  that  the  changing  of  forest 
areas  to  other  forms  of  vegetation  possibly  can 
affect  precipitation  or  influence  droughts.  Stress 
is  laid  on  the  fact  that  some  land  is  left  bare  and 
then  is  eroded  into  deep  gullies.  This  is  true,  but 
the  fault  is  one  that  may  be  corrected  by  a  proper 
system  of  plowing  and  cultivation.  And  at  most 
the  area  so  eroded  is  so  infinitesimal  in  comparison 
to  the  vast  regions  changed  from  forests  to  growing 
crops  as  to  be  negligible. 

Influence  of  Ocean  Currents  on  Climate.  Climates 
are  markedly  influenced  by  the  currents  of  oceans. 
Charts  15  and  16  show  the  normal  wind  circulations 
of  the  globe;  note  that  the  centers  of  the  great 
swirls  are  coincident  with  the  location  of  the  High 
and  the  Low  centers  of  action  located  on  Charts  1 
and  2.  Next  observe  Chart  13,  showing  the  ocean 
currents,  and  it  will  be  seen  at  once  how  closely  the 
circulation  of  the  great  ocean  currents  follows  that 
of  the  winds,  due  to  the  friction  of  the  air  upon  the 
water,  and  to  the  interposition  of  bodies  of  land 
that  turn  about  or  deflect  the  currents. 

Water  has  a  greater  capacity  for  heat  than  nearly 
any  other  substance.  It  requires  ten  times  the 
quantity  of  heat  to  raise  a  pound  of  water  one  de- 


HOW  CLIMATE  IS  CONTROLLED    201 

gree  that  it  does  a  pound  of  iron.  The  oceans 
therefore  store  up  vast  quantities  of  the  heat  of  the 
sun  and,  unlike  the  continents,  distribute  this  heat 
northward  and  southward  without  regard  to  lati- 
tude. Much  of  the  heat  of  the  tropics  is  thus  trans- 
ported far  northward  and  southward  from  the 
equator.  The  extensive  eddy-like  circulation  of 
the  south  half  of  the  North  Atlantic  Ocean  sends 
currents  northward  along  the  coast  of  the  United 
States  which  set  eastward  at  latitude  40°.  A  part 
of  these  reach  the  coast  of  Spain  and  then  turn 
south ;  the  greater  part  spread  out  in  mid-ocean  and 
move  northeast,  bathing  the  coasts  of  the  British 
Islands,  Iceland,  and  Norway.  They  still  retain 
some  of  the  heat  that  they  absorbed  from  a  tropical 
sun,  and  they  therefore  give  to  the  coasts  that  they 
reach  a  higher  temperature  than  they  would  have 
if  the  ocean  waters  were  moving  from  the  north,  or 
than  they  would  have  if  there  were  no  currents  at 
all.  On  Chart  14  note  how  the  isothermal  lines 
are  carried  northward  by  these  currents  as  they 
cross  the  Atlantic  Ocean.  The  Gulf  Stream  mingles 
with  these  northeast  currents  but  adds  little  to 
their  temperatures,  for  the  general  ocean  circula- 
tion would  produce  practically  the  same  effects  if 
there  were  no  Gulf  Stream. 


202  THE  NEW  AIR  WORLD 

Follow  the  currents  down  the  coast  of  Spain  and 
of  northeast  Africa;  then  note  on  Chart  14  the 
southward  trend  of  the  lines  of  equal  temperature, 
as  the  currents  bring  colder  water  southward  to 
cool  the  air.  Next  examine  the  currents  of  the 
Pacific  and  the  isothermals.  The  currents  moving 
northward  towards  the  equator  along  the  west 
coast  of  South  America,  and  those  moving  south- 
ward, also  toward  the  equator,  along  the  west  coast 
of  the  United  States  and  Mexico  cause  a  bulging 
of  the  isothermal  lines  from  the  positions  that  they 
would  occupy  if  there  were  no  currents  coming  from 
colder  regions. 

Influence  of  the  Gulf  Stream  on  Climate.  From 
either  side  of  the  equator  the  surface  winds  (Charts 
15  and  16)  blow  the  water  westward,  causing  what 
are  known  as  the  "  Equatorial  Currents  "  (Chart  13). 
The  eastward  projection  of  the  coast  of  South 
America  divides  the  Atlantic  equatorial  current 
into  two  parts;  one  goes  south  along  the  coast  of 
South  America  and  sets  up  the  circulation  in  the 
South  Atlantic,  which  sweeps  north  along  the  south- 
west coast  of  Africa.  The  other  passes  to  the 
northwest,  a  part  setting  up  the  North  Atlantic 
circulation  and  the  remainder  sweeping  through  the 
Windward  Islands  and  storing  itself  in  the  Gulf 


HOW  CLIMATE  IS   CONTROLLED     203 

of  Mexico,  whence  it  is  driven  out  at  a  velocity  of 
some  five  miles  per  hour  through  the  narrow  channel 
between  Key  West  and  Cuba.  Here  it  has  a  depth 
of  half  a  mile  and  a  width  of  forty  miles.  Its  ve- 
locity is  accelerated  because  it  enters  the  Gulf  in  a 
broad  sweep  and  passes  out  through  a  constricted 
channel.  It  retains  its  individuality  as  a  warm 
river  passing  through  the  ocean  because  of  its  greater 
velocity  and  higher  temperature  than  the  waters 
in  which  it  finds  itself  soon  after  it  leaves  the  Gulf ; 
but  it  gradually  merges  with  the  great  Atlantic 
circulation  as  it  passes  to  the  middle  of  the  ocean. 
It  is  the  opinion  of  the  writer  that  its  influence  on 
climate  has  been  exaggerated,  that  the  warming 
of  Europe  that  is  credited  to  the  Gulf  Stream 
is  accomplished  by  the  mere  presence  of  the  ocean 
to  the  westward  and  to  the  general  circulation  of 
that  ocean  without  regard  to  the  wonderful  phenome- 
non known  as  the  Gulf  Stream. 

Effect  of  Valleys  on  Day  and  Night  Temperatures. 
Valleys  affect  temperatures  in  proportion  to  their 
depth  and  width.  A  deep,  narrow  valley  might 
have  the  effect  illustrated  by  Figure  27,  if  the  time 
were  summer  and  the  sky  clear.  During  the  day- 
time radiation  would  warm  the  interior  so  that  the 
bottom  of  the  valley  would  have  a  much  higher 


204 


THE  NEW  AIR  WORLD 


temperature  than  the  free  air  at  the  top  of  the  valley, 
and  the  movement  of  the  air  would  be  sluggishly 
down  the  center  and  up  the  sides  of  the  depression. 


Summer  day    temperature  in  a  Summer  night  temperature  in  the 

narrow  valley.  same  valley. 

FIGURE  27. 

During  nighttime  all  the  conditions  would  be  re- 
versed. Vegetation,  losing  heat  by  radiation  much 
faster  than  the  air,  would  cool  the  latter  as  it  came 
in  contact  with  the  sides  of  the  valley.  The  air 
would  slowly  descend  along  the  sides  through  gain 
in  specific  gravity  and  collect  at  the  bottom  with 
a  temperature  much  lower  than  it  had  when  it 
started  its  descent. 

Effect  of  Mountains  on  Climate.  The  rarity  of 
the  atmosphere  of  mountains  readily  allows  the 
rays  of  the  sun  to  pass  through  it  and  thus  the  sur- 


HOW   CLIMATE  IS  CONTROLLED    205 

face  of  mountains  is  quickly  warmed,  but  the  same 
conditions  permit  a  rapid  radiation  at  night,  so  that 
there  are  considerable  extremes  of  temperature. 
Air  cooled  by  contact  with  a  mountain  may  flow  down 
its  sides  at  night  and  collect  in  depressions  below, 
often  causing  frost  on  still  nights  where  the  temper- 
ature higher  up  is  much  above  freezing.  Moun- 
tains may  be  more  cloudy  and  rainy  than  plains, 
for  the  currents  of  air  that  cross  them  must  rise, 
and  in  rising  they  cool  by  expansion  and  often  reach 
the  dew  point  of  the  air,  moisture  being  precipitated 
in  the  form  of  clouds,  rain,  or  snow.  Often  a  peak 
is  constantly  capped  with  a  crown  of  clouds.  Moun- 
tains may  intercept  vapor-bearing  winds  from  oceans, 
force  them  to  such  an  elevation  that  their  vapor  is 
largely  precipitated  on  the  windward  side  of  the 
mountain,  and  receive  them  on  the  leeward  side 
as  dry,  rainless  winds.  Vast  desert  areas  are  often 
the  result.  A  good  example  is  presented  in  the  case 
of  the  Pacific  coast  mountains  and  the  desert  plateau 
to  the  east. 

Mountain  peaks  may  be  covered  with  snow,  even 
though  they  be  located  in  the  tropics,  if  their  eleva- 
tion be  sufficient.  This  is  because  the  absorption  of 
both  incoming  and  outgoing  radiation  is  so  much 
greater  in  the  lower  reaches  of  the  atmosphere, 


206  THE  NEW  AIR  WORLD 

where  the  water  vapor  is  densest.  Wherever  ob- 
servations have  been  made  they  have  shown  that 
the  temperature  of  the  air  on  high  mountain  peaks 
and  crests  and  for  a  distance  of  one  to  three  hundred 
feet  above  them  is  cooler  than  adjacent  free  air  of 
the  same  height,  due  to  upward  deflection  of  air 
currents  and  their  cooling  by  expansion,  and  to 
radiation  from  the  peak. 

The  Himalayan  Mountains  exercise  a  profound 
effect  on  the  climate  of  Asia.  The  monsoon  (any 
wind  that  alternates  annually  in  direction  or  force) 
of  summer  brings  the  moist  air  from  the  Bay  of 
Bengal  and  precipitates  torrential  rains  from  it  as  it 
ascends  to  higher  and  higher  elevations  in  passing 
over  the  great  heights  of  the  mountains.  At  a 
place  four  thousand  feet  above  the  sea  and  not 
distant  from  Calcutta,  the  annual  rainfall  is  466 
inches,  while  the  average  for  most  of  the  region  east 
of  the  Mississippi  River  is  only  forty  inches.  More 
than  forty  inches  have  been  known  to  fall  in  one  day 
in  the  Himalayan  Mountains.  As  in  the  case  of 
all  very  high  mountains,  the  rainfall  increases  in 
these  mountains  up  to  a  certain  elevation  and  then 
decreases.  North  of  the  mountains  the  monsoon 
passes  into  the  interior  of  Asia  with  withering  dryness 
and  vast  deserts  are  the  result. 


HOW  CLIMATE  IS  CONTROLLED    207 


Figure  28  graphically  presents  the  average  monthly 
temperature  and  rainfall  of  typical  places  in  North 

MlimrillllUlliHW  HHUIHHIItHltWIUI  HI*HI*I»HI*HM»H 


St.Paul.  Minn. 


Toronto,  Canada 


>&n  Francisco.  Cftl* 


Kansas  City,  Mo. 


Pittsburgh,  Pa. 


Los  Angeles,  Cal. 


Dallas,  Texas. 


\ 


Savannah,  Go. 


Mexico  City 


Vera  Cruz,  Mexico 


FIG.  28.  —  Average  Monthly  Temperature  and  Rainfall  of  Typical  Places  in 
North  America.     (Huntington  and  Gushing.) 


208 


THE  NEW  AIR  WORLD 


America,  and  Figure  29  of  places  in  the  Old  World. 
Here  may  be  seen  every  phase  of  climate  from  tropi- 


VUdlTOU* 


/       \ 


ValcnUa 


Vienna 


Pekia 


Lisbon 


ConsUntinople 


Hongkong 


FIG.  29.  —  Average  Monthly  Temperatures  and  Rainfall  of  Typical 
Places  in  the  Old  World.  (From  "  Principles  of  Human  Geography." 
John  Wiley  &  Sons.) 


HOW  CLIMATE  IS  CONTROLLED    209 

cal  to  temperate  and  to  cold,  and  from  marine  to 
continental.  By  studying  the  winds  on  Charts  15 
and  16  and  the  ocean  currents  on  Chart  13,  the 
reader  should  be  able  to  find  an  explanation  for  the 
different  conditions  shown.  For  example:  Maza- 
tlan  and  Vera  Cruz  are  both  on  the  coast  of  Mexico, 
the  first  on  the  west  and  the  latter  on  the  east. 
Each  has  a  rainy  period  in  the  summer,  but  at  Vera 
Cruz  the  rain  begins  earlier  and  lasts  later  and  is 
much  heavier.  The  reason  is  that  they  both  have 
north  winds  in  winter  (Charts  15  and  16),  but  in 
summer  Vera  Cruz  receives  winds  direct  from  the 
Gulf  of  Mexico  and  at  Mazatlan  the  winds  continue 
to  blow  from  the  north,  with  but  a  slight  inclination 
landward.  Again,  the  explanation  for  the  fact  that 
Mazatlan  has  a  monthly  range  of  temperature  from 
60°  in  winter  to  80°  in  summer,  while  Vera  Cruz 
has  a  range  of  only  70°  to  80°  is  found  in  the  wind 
direction. 

The  City  of  Mexico  is  wonderfully  favored  by 
climate.  Here  a  moderate  rainfall  occurs  from 
May  to  September.  The  oceans  are  not  far  distant 
on  either  side,  as  distances  are  measured  continen- 
tally,  but  its  great  elevation  on  a  table-land  relieves 
it  of  the  torrential  rains  usual  to  the  tropics;  and 
yet  it  is  close  enough  to  marine  influence  so  that  its 


210  THE  NEW  AIR  WORLD 

air  has  not  the  nerve-irritating  dryness  of  the  plateau 
of  the  Rocky  Mountains,  and  it  has  a  remarkable 
evenness  of  temperature  between  winter  and  summer, 
with  a  monthly  range  between  50°  and  60°.  Its 
range  between  day  and  night  is  sufficient  to  be 
stimulating. 

Still  looking  at  Figure  28,  note  the  remarkable 
similarity  between  the  climate  of  Pittsburg  and 
Toronto.  Each  has  about  the  same  rainfall  and  it 
is  almost  equally  distributed  throughout  the  months 
of  the  year.  The  only  difference  is  that  Toronto 
is  a  little  colder.  St.  Paul  and  Kansas  City,  typical 
of  the  climate  in  the  interior  cities,  have  a  small 
amount  of  precipitation  in  winter,  considerable  in 
summer,  and  a  wide  range  of  temperature;  while 
the  Pacific  coast  cities  have  dry  summers,  and  winters 
that  vary  from  three  inches  of  rain  at  Los  Angeles 
to  fourteen  inches  at  Astoria,  with  no  excesses  in 
temperature. 

Temperatures  Aloft  in  the  Atmosphere.  Kite 
and  balloon  observations  have  not  been  continued 
long  enough,  nor  have  they  been  made  at  a  sufficient 
number  of  places,  to  give  one  the  data  from  which 
the  climate  of  any  considerable  altitude  in  the  free 
air  may  be  determined,  but  from  a  large  number  of 
free  balloon  observations  made  with  self-recording 


HOW  CLIMATE  IS   CONTROLLED    211 

instruments,  in  the  middle  latitudes  of  this  and 
foreign  countries,  Figure  1  (page  12)  has  been 
constructed,  which  shows  the  manner  in  which  the 
temperature  decreases  with  elevation  up  to  eighteen 
kilometers  (eleven  miles).  Note  how  rapidly  it  falls 
with  elevation  up  to  eleven  and  a  half  kilometers 
(about  seven  miles).  This  depth  of  air  measures 
the  thickness  of  the  turbulent  stratum  in  which 
cyclones  and  anti-cyclones  operate.  At  its  top  the 
temperature  always  is  about  64°  below  zero  in  winter 
and  70°  below  in  summer.  And  right  here  occurs 
a  most  wonderful  phenomenon,  —  one  of  which 
scientists  were  entirely  ignorant  less  than  two 
decades  ago.  At  first  it  was  thought  that  there 
was  something  wrong  with  the  recording  thermom- 
eters, for  they  failed  to  register  falling  tempera- 
ture with  gaining  altitude  after  the  storm  stratum 
was  passed  at  seven  miles.  Then  it  was  noted  that 
all  instruments  displayed  the  same  peculiarity,  and 
the  "  Isothermal  Stratum  "  (equally  heated  region) 
was  discovered,  in  which  the  temperature  maintains 
the  same  degree  of  intense  cold  so  far  as  exploration 
had  been  made.  From  Mount  Weather,  under  the 
direction  of  the  writer,  a  balloon  was  flown  to  nine- 
teen and  one  tenth  miles  before  it  exploded  and  sent 
a  parachute  gently  down  to  earth  with  its  precious 


212  THE  NEW  AIR  WORLD 

record.  This  flight  showed  practically  no  change  in 
temperature  after  the  isothermal  stratum  was 
reached.  (See  Chapter  III.)  One  is  reasonably 
safe  in  assuming  that  there  is  no  oxygen  beyond  an 
altitude  of  thirty  miles  and  that  at  fifty  miles  the 
nitrogen  becomes  inappreciable,  and  that,  therefore, 
the  temperature  must  shade  away  to  practically 
nothing  when  the  void  of  outer  space  is  reached, 
notwithstanding  the  presence  of  the  newly-dis- 
covered isothermal  stratum  nearer  the  earth. 


CHAPTER  XII 
CIVILIZATION  FOLLOWS  THE  STORM  TRACKS 

THE     MOST     DOMINANT      RACES  —  THOSE     THAT     BEST     CO- 
ORDINATE    THE     MENTAL     AND     PHYSICAL     FACULTIES 

ARE    FOUND     TO    EXIST    UNDER    CERTAIN    CLIMATIC 

CONDITIONS CHANGE       THE       CLIMATE       AND       YOU 

CHANGE  THE    MAN 

IN  a  climate  where  man  needs  little  protection 
from  the  elements,  where  he  may  lie  upon  his  back 
in  the  shade  and  with  his  bare  toes  pick  wild  growing 
fruit  to  nourish  his  body,  one  will  find  no  great 
leaders  in  art,  literature,  science,  statecraft,  or 
industry ;  likewise,  in  the  Arctic,  where  man  simply 
gathers  enough  blubber  to  supply  his  animal  wants 
and  then  burrows  beneath  the  snows  of  fierce  winters, 
one  will  not  find  leadership  or  creative  genius.  The 
regions  of  greatest  human  potential  are  limited  to 
such  portions  of  the  temperate  zone  as  have  an 
abundance  of  rainfall,  frequent  changes  in  the 
weather,  and  an  alluvial  soil.  In  other  words,  the 
most  perfect  composite  of  human  resourcefulness 


214  THE  NEW  AIR  WORLD 

is  found  where  nature  is  neither  so  fierce  as  to  crush 
human  aspiration,  nor  yet  so  gentle  as  to  lull  human 
desire. 

Humbolt  says :  "  Man  is  the  product  of  soil 
and  climate;  he  is  brother  to  the  tree,  the  rocks, 
and  the  animals."  We  shall  endeavor  to  show  that 
civilization  and  the  greatest  human  potential  follow 
the  storm  tracks  of  the  world,  and  that  climate  is  the 
most  important  factor  in  his  environment,  for  with- 
out its  proper  adjustment  to  his  needs  the  richest 
soil  and  the  most  beneficent  form  of  government 
fail  to  bring  out  the  best  that  is  in  him.  Empire 
is  determined  as  much  by  direction  and  force  of  the 
wind  and  changes  in  the  weather  as  by  the  scheming 
of  politicians,  the  deep-laid  plans  of  diplomats,  or 
the  marshaling  of  battalions. 

The  first  thing  that  vigorous  man  requires  is 
active  atmospheric  conditions  and  in  his  migrations 
he  follows  the  climatic  lines  that  appease  his  desires. 
A  climate  of  little  change  between  day  and  night 
and  between  winter  and  summer  is  soothing  and  at 
the  same  time  deadening  to  the  human  faculties ; 
but  changes  should  be  frequent  rather  than  violent. 
The  daring,  the  creative,  the  pioneering,  the  per- 
sistent spirits  of  mankind,  like  snow  birds  showering 
themselves  with  icy  crystals,  revel  in  the  cool  air, 


CIVILIZATION  FOLLOWS  THE  STORM    215 

the  perpetual  oscillations  of  temperature,  and  the 
frequent  changes  from  sunshine  to  cloud  that  per- 
tain to  the  regions  where  storms  are  most  numerous. 

Some  days  the  mind  works  with  a  joyous  lucidity, 
the  spirits  are  high  and  the  step  elastic  and  vigorous. 
On  another  day  the  mind  is  turbid ;  it  works  slowly 
and  hesitates  in  reaching  decisions;  one  is  listless 
and  lacking  in  physical  energy.  On  both  days  one 
may  be  in  a  perfectly  normal  physical  and  mental 
condition,  except  for  the  effects  of  the  weather. 

Under  the  direction  of  the  writer,  comparison  of 
the  records  of  crimes  of  violence  with  the  weather 
records,  by  officials  of  the  U.  S.  Weather  Bureau, 
showed  a  marked  increase  of  crime  of  this  sort  during 
midsummer  as  against  midwinter,  and  the  extremely 
hot  summer  showed  more  crime  than  the  cool  ones. 
During  recent  years  Ellsworth  Huntington  has 
made  exhaustive  and  extremely  valuable  studies 
of  the  records  of  piece  workers  in  factories  and 
elsewhere  from  New  England  and  the  Middle  At- 
lantic States  down  to  Florida  and  the  Gulf  of  Mexico, 
and  also  of  the  mental  activities  of  the  cadets  at 
West  Point  and  Annapolis,  and  of  the  students  in 
colleges,  as  shown  by  their  recitation  markings.1 

1  "  Principles  of  Human  Geography  ",  Huntington  and  Gushing.  John 
Wiley  &  Sons,  New  York. 


216  THE  NEW  AIR  WORLD 

He  has  compared  these  records  with  the  weather  day 
by  day  and  hour  by  hour  and  definitely  shown 
a  direct  relation  between  variations  in  the  meteoro- 
logical conditions  and  human  efficiency.  He  finds 
that  people's  health  and  strength  are  greatest 
when  the  temperature  falls  to  between  56°  and  60° 
at  night  and  rises  to  somewhere  between  68°  and 
72°  during  the  day.  He  has  determined  the  op- 
timum, or,  in  other  words,  the  meteorological  con- 
ditions best  suited  to  man's  health,  happiness,  and 
efficiency.  For  mental  activity  the  optimum  tem- 
perature is  much  lower  than  for  physical.  People's 
minds  are  more  alert,  they  reason  with  greater 
analytic  precision,  they  have  greater  confidence  in 
their  decisions  and  they  are  more  optimistic,  when 
the  temperature  falls  to  about  freezing  at  night 
and  rises  to  45°  or  50°  during  the  day.  Except  for 
limited  activities,  the  most  efficient  man  is  the  one 
in  whom  the  mental  and  physical  faculties  are  most 
perfectly  coordinated.  Broadly  speaking,  this  agree- 
ment may  be  best  accomplished  during  times  when 
the  daily  temperature  ranges  between  45°  and  65°. 

Excessive  humidity  in  midsummer  —  eighty  per 
cent,  or  over  —  is  harmful  and  adds  enormously 
to  the  death  rate;  on  the  other  hand,  some  of  the 
worst  colds  may  come  from  extreme  dryness  in 


CIVILIZATION  FOLLOWS  THE  STORM    217 

summer.  It  may  be  found  feasible  to  dry  the  air 
in  sleeping  and  living  rooms  in  summer  when  the 
humidity  is  too  high,  by  closing  the  apartment  and 
forcing  the  air  over  or  through  calcium  carbide  or 
melting  ice  and  salt.  When  the  air  is  kept  at  65  to  70 
per  cent,  humidity  in  winter  one  will  feel  comfortable 
in  a  much  lower  temperature  —  about  68°  —  than 
when  the  air  is  extremely  dry,  as  it  usually  is  in  the 
average  living  apartment.  With  a  relative  humidity 
of  30  to  40  per  cent,  which  one  now  often  finds 
in  warm  houses  in  winter,  the  temperature  may 
be  forced  up  to  75°  or  over  and  still  one  may  feel 
cold,  because  of  the  rapid  evaporation  from  the  pores 
of  the  skin,  and  the  cold  created  inside  the  clothing 
by  the  heat  lost  in  the  process  of  evaporation. 
Bear  in  mind  that  perspiration  is  going  on  at  all 
temperatures,  even  if  one  is  unconscious  of  the  fact. 
In  the  most  populous  portions  of  the  United  States 
there  are  two  periods  of  maximum  efficiency  and  two 
of  minimum  each  year.  Let  us  consider  that  wonder- 
ful region  including  southern  New  England,  the  Mid- 
dle Atlantic  States,  the  Ohio  Valley,  and  westward 
to  the  Rocky  Mountains.  Again  referring  to  the 
records  of  Huntington  we  find  that  human  energy 
is  greatest  in  October ;  the  output  of  factory,  mine, 
and  counting  room  is  greater  per  man  than  at  any 


218  THE  NEW  AIR  WORLD 

other  time  of  the  year  and  the  product  of  menta] 
effort  is  greater  and  of  higher  quality.  Likewise 
disease  is  less  and  the  death  rate  the  least.  From 
this  time  there  is  a  loss  in  energy  until  January  or 
February,  when  vitality  and  efficiency  may  have 
dropped  twenty  to  thirty  per  cent.  Then  there  is 
a  gain  until  May  or  early  June,  when  the  conditions 
of  health  and  efficiency  are  nearly  equal  to  the  most 
favorable  time  of  the  year  in  October.  Again  there 
is  a  loss  until  the  middle  of  July,  when  a  second 
minimum  occurs ;  physical  and  mental  energy  are 
at  a  low  ebb  and  the  death  rate  Is  high.  Diseases 
are  not  quite  the  same  as  in  winter,  as  stomach 
troubles  are  more  common  than  colds.  The  hotter 
the  summer  and  the  colder  the  winter  the  less 
favorable  are  the  conditions  of  human  existence. 

As  there  is  a  certain  optimum  beyond  which 
diurnal  and  annual  range  of  temperature  cannot 
increase  without  a  loss  in  energy,  so  there  is  a  lim- 
itation in  latitude  beyond  which  the  favorable 
climatic  conditions  decrease  as  one  goes  north- 
ward or  southward.  As  an  example,  Canada  and 
northern  Maine  have  but  one  unfavorable  period, 
which  is  the  entire  winter.  The  people  of  these 
regions  are  at  their  greatest  potential  July  to  Septem- 
ber, after  which  they  show  a  steady  decline  as  the 


CIVILIZATION  FOLLOWS  THE  STORM    219 

severity  of  the  northern  winter  draws  upon  their 
vitality,  until  in  January  and  February  their  min- 
imum is  below  that  of  regions  considerably  farther 
south  for  the  same  period. 

From  the  most  favorable  climatic  area  in  the 
middle  latitudes  —  and  the  entire  world  possesses 
none  more  favorable  or  of  greater  extent  than  that 
possessed  by  the  United  States  —  the  loss  of  health 
and  strength  due  to  the  enervating  effects  of  heat, 
high  humidity,  and  insufficient  temperature  oscil- 
lations increases  as  one  goes  toward  the  equator. 
In  Florida  and  the  southern  third  of  the  Gulf  States 
there  is  but  one  favorable  period,  the  short  winter. 
The  enervating  conditions  still  further  are  manifest 
as  one  proceeds  farther  southward. 

In  the  "Principles  of  Human  Geography",  it  is 
stated  that "  in  Central  France  and  Southern  Germany 
the  seasonal  variations  in  health  and  strength  are 
much  the  same  as  in  Boston,  New  York,  Cleveland, 
and  Detroit.  That  is,  people  are  most  healthy  and 
strong  in  October  and  early  November  and  again 
in  May  and  early  June,  while  they  are  weakest  and 
most  subject  to  disease  in  January,  February,  and 
early  March,  and  again  in  July  and  August.  Farther 
north,  for  example,  in  Scotland,  Scandinavia,  and 
Finland,  the  summer  is  the  best  time  of  the  whole 


220  THE  NEW  AIR  WORLD 

year  and  the  winter  the  worst.  To  the  south,  on 
the  contrary,  in  Italy,  Spain,  and  Greece,  the  harm- 
ful effect  of  the  winter  decreases  and  that  of  summer 
increases,  until  finally  on  the  south  side  of  the  Med- 
iterranean the  winter  is  much  the  best  time  of  the 
whole  year,  while  the  long  summer  greatly  diminishes 
the  people's  efficiency  and  increases  disease  and 
death." 

As  the  highest  mental  activity  is  coincident  with 
temperatures  lower  than  those  that  induce  the 
greatest  physical  energy,  it  naturally  follows  that 
in  the  Ohio  Valley,  southern  New  England,  and  the 
Middle  Atlantic  States  the  mental  worker  is  at 
his  maximum  in  November  instead  of  October,  and 
April  instead  of  May. 

Chart  17  shows  how  human  energy  would  be 
distributed  over  the  earth  if  it  depended  on  climate 
alone.  It  is  remarkable  how  almost  exactly  it 
agrees  with  what  we  know  to  be  the  distribution  of 
the  great  political  power.  Japan  is  meant  to  be 
included  in  the  region  of  high  power,  but  the  scale 
of  the  chart  is  too  small  to  make  this  plain. 

From  the  time  when  man  began  to  lose  his  tribal 
instinct  and  to  assume  national  consciousness,  hi 
Egypt,  the  Mesopotamian  Valley,  and  the  region 
between  the  Caspian  Sea  and  the  Persian  Gulf,  he 


CIVILIZATION  FOLLOWS  THE  STORM 

has  been  founding  empires  of  more  or  less  enduring 
nature,  and  with  few  exceptions  has  builded  towards 
the  west,  in  the  face  of  the  prevailing  winds.  The 
center  of  Empire  has  steadily  migrated  along  the 


CHART  17.  —  MAP  OF  CLIMATIC  ENEBGT.     (Huntington  and  Gushing.) 

paths  of  greatest  storm  frequency.  Examine  Charts 
10,  11,  and  18  and  note  the  relation  between 
density  of  population  and  the  closeness  of  the  storm 
tracks.  The  figures  at  the  center  of  each  brace 
indicate  the  number  of  storms  that  originated  in  the 
region  of  the  brace  during  a  ten-year  period,  and 
the  lines  leading  from  the  brace  show  the  tracks 
followed  by  the  centers  of  the  storms.  Bear  in  mind 
that  each  storm  covered  an  area  of  from  five  hundred 
to  one  thousand  miles  in  diameter,  that  it  was  a  vast 
rotating  eddy  in  the  atmosphere,  and  that  its  center 


222 


THE  NEW  AIR  WORLD 


of  rotation  followed  one  of  these  storm  tracks. 
Twelve  storms  came  from  the  West  Indies  during 
these  ten  Augusts,  fifty-seven  from  the  Rocky 
Mountains  and  none  from  the  Pacific  Ocean ;  while 
in  the  ten  Januaries  none  came  from  the  West 
Indies  and  but  twenty-two  from  the  Pacific  Ocean. 


CHART  18.  —DENSITY  OF  POPULATION  IN  THE  UNITED  STATES,  1910. 

But  the  point  to  which  your  attention  is  directed 
is  that,  no  matter  what  the  origin,  the  tendency  of 
each  storm  was  to  move  towards  the  Ohio  Valley, 
Pennsylvania,  New  York,  New  Jersey,  and  New 
England.  This  tendency  gives  to  these  regions 
the  most  frequent  changes  in  weather,  with  alter- 
nations of  sunshine  and  clouds,  and  changes  in  tern- 


CIVILIZATION  FOLLOWS  THE  STORM    223 

perature  and  air  pressure  —  conditions  essential  to 
the  development  of  the  greatest  human  potential. 
Here  population  is  the  densest,  civilization  the 
highest,  and  the  products  of  man's  brain  and  hand 
greater  and  more  diversified  than  elsewhere  in 
this  country,  and  probably  than  elsewhere  in  the 
world.  The  United  States  is  abundantly  blessed, 
for  nearly  its  entire  area  is  under  the  influence  of 
high  atmospheric  potential.  Only  the  region  adja- 
cent to  the  Gulf  of  Mexico  and  the  southwest  is 
outside  of  the  favored  area,  and  here  the  conditions 
are  charted  as  medium,  and  not  poor;  at  least  not 
poor  in  comparison  with  many  more  purely  tropical 
regions. 

To-day  the  Empire  of  Human  Greatness  is  cen- 
tered over  the  United  States,  that  is  to  say,  great- 
ness as  expressed  in  material  wealth,  population, 
and  homogeneously  knit  political  institutions.  Will 
it  continue  its  westward  migration,  or  will  it  remain 
here  indefinitely  for  the  working  out  of  a  civilization 
higher  than  yet  has  come  to  any  of  the  nations  of 
the  past,  or  to  other  of  those  of  the  present  ?  So  far 
as  atmospheric  activities  have  to  do  with  its  transla- 
tion from  place  to  place,  we  may  derive  comfort  from 
the  fact  that  storm  tracks  do  not  cross  the  Pacific 
Ocean  as  freely  as  they  do  the  Atlantic.  In  fact  our 


224  THE  NEW  AIR  WORLD 

Rocky  Mountains  are  a  barrier  to  the  passage  of 
summer  storms  (Chart  10)  and  a  reference  to  Chart  11 
will  show  that  of  ninety-five  winter  storms  that 
crossed  our  continent  during  the  ten  Januaries  of 
which  the  chart  is  a  record  only  twenty-two  came 
into  our  area  from  the  Pacific ;  and  we  know  that 
these  twenty-two  largely  originated  off  our  coast 
somewhere  between  Hawaii  and  the  Aleutian  Islands. 
Let  us  hope  that  the  center  of  earthly  power  has 
reached  the  end  of  its  westward  journey  and  that 
here  it  shall  remain,  always  to  exercise  a  just  and 
beneficent  influence  upon  the  less  favored  portions 
of  the  earth. 

Enough  has  been  said  to  indicate  that  climate  is 
nearly  as  important  to  animal  life  as  it  is  to  the 
vegetable  existence,  and  that  a  cold  climate,  if  it  be 
not  so  extreme  as  to  limit  the  production  of  cereal 
crops,  and  has  frequent  changes  in  temperature, 
pressure,  sunshine,  and  cloud,  favors  the  development 
of  hardy  and  resourceful  races  of  men ;  in  fact,  that 
no  dominating  race  can  exist  without  such  stim- 
ulating conditions  of  climate. 


CHAPTER  XIII 
HAS  OUR  CLIMATE  CHANGED? 

POPULAR  OPINION  ERRONEOUS,  AS  THERE  IS  NO  CHANGE 
WITHIN  THE  PERIOD  OF  AN  INDIVIDUAL  LIFE,  BUT 
MOMENTOUS  CHANGES  HAVE  OCCURRED  SINCE  THE 
BEGINNING  OF  THE  CHRISTIAN  ERA 

One  of  the  hallucinations  entertained  by  nearly 
every  adult  person  is  that  the  climate  has  changed 
since  he  was  young.  No  matter  what  the  scientists 
may  say,  he  knows  that  it  has  changed.  Fifty  years 
ago  did  he  not  trudge  to  school  for  months  every 
winter  in  snow  knee-deep?  Have  not  the  old 
swimming  holes  in  the  brook  dried  up?  Yes,  he 
is  a  positive  witness  to  an  affirmative  answer.  Even 
the  river  of  his  boyhood,  whose  broad  expanse  he 
conquered  in  a  swimming  contest  at  the  tender 
age  of  ten  —  as  he  views  it  after  an  absence  of  a 
quarter-century  —  has  dwindled  to  little  more  than 
a  creek,  across  which  one  easily  may  hurl  a  stone. 
Talk  to  him  about  no  change  in  climate.  He's 
been  right  on  the  spot,  and  knows.  For  all  this,  there 


226  THE  NEW  AIR  WORLD 

has  been  no  change  during  the  lifetime  of  this  man ; 
nor  has  there  ever  been  during  the  life  period  of  any 
individual.  Mutations,  to  be  sure,  are  going  on  all 
the  time,  but  they  are  so  minute  that  they  do 
not  accumulate  a  measurable  quantity  except  in 
periods  of  hundreds  or  thousands  of  years.  It  is 
not  the  climate  that  has  changed;  it  is  the  man. 
The  natural  action  of  the  stream  may  have  filled  the 
swimming  holes;  or  the  stream  may  have  entirely 
disappeared  through  much  of  the  contiguous  area 
being  brought  under  cultivation  and  the  water  that 
formerly  supplied  its  flow  being  utilized  in  the 
production  of  cultivated  crops,  which  actually  make 
use  of  as  much  if  not  more  rainfall  than  the  forest 
that  formerly  lined  its  sinuous  banks  and  covered 
the  near-by  lowland.  And  then,  snow  knee-deep 
to  a  boy  of  ten  hardly  comes  up  to  the  ankles  of  a 
man  of  six  feet  two.  Again,  no  one  can  remember 
the  climate  of  his  boyhood;  he  cannot  carry  the 
average  in  his  mind ;  all  that  he  can  remember  are 
a  few  instances  of  unusual  conditions  which  because 
of  their  unusual  character  left  an  impress  upon  his 
mind.  The  river  is  just  as  wide  as  it  ever  was 
during  the  period  of  his  lifetime,  or  that  of  his  father, 
or  of  his  grandfather ;  but  he  has  lived  on  the  broad 
Mississippi  for  many  years,  and  when  he  goes  back 


HAS  OUR  CLIMATE   CHANGED?      227 

to  the  scenes  of  his  youth,  his  concept  of  what 
constitutes  a  river  has  undergone  a  revolutionary 
change  since  he  left  the  parental  roof  to  go  forth 
and  conquer  the  world. 

An  examination  of  the  personal  papers  of  Thomas 
Jefferson,  in  the  State  Department  at  Washington, 
by  an  official  of  the  Weather  Bureau,  revealed  a 
number  of  most  interesting  incidents  in  connection 
with  the  weather  observations  made  by  the  author 
of  the  Declaration  of  American  Independence.  He 
says: 

"  A  change  in  climate  is  taking  place  very  sensibly. 
Both  heats  and  colds  are  becoming  much  more 
moderate  within  the  memory  of  even  the  middle- 
aged.  Snows  are  less  frequent  and  less  deep.  They 
do  not  often  lie  below  the  mountains  more  than  one, 
two,  or  three  days,  and  very  rarely  a  week.  The 
snows  are  remembered  to  have  been  more  frequent, 
deep,  and  of  long  continuance.  The  elderly  inform 
me  that  the  earth  used  to  be  covered  with  snow 
about  three  months  in  every  year." 

But  Jefferson  and  his  neighbors  were  mistaken. 
Never  during  the  period  of  authentic  history  has 
the  snow  covered  the  ground  in  Virginia  an  average 
of  three  months  per  year,  or  three  months  for  a 
single  year.  These  old  inhabitants  were  like  those 
of  to-day,  who  remember  only  the  abnormalities 


228  THE  NEW  AIR  WORLD 

of  climate  of  twenty-five  or  fifty  years  ago,  and 
in  comparing  the  unusual  conditions  of  long  ago 
with  the  average  of  the  present  time  they  are  de- 
ceived. I  have  known  intelligent  and  well-meaning 
persons  to  declare  that  they  knew  from  personal 
recollection  that  the  climate  of  their  particular 
places  of  residence  had  changed  since  they  were 
young;  that  they  had  stable  landmarks  to  show 
that  the  streams  were  drying  up,  the  rainfall  growing 
less,  and  the  winters  becoming  milder,  notwith- 
standing the  fact  that  carefully  taken  observations 
of  temperature  and  rainfall  for  each  day  for  over 
one  hundred  years  right  at  their  places  of  abode 
showed  no  change  in  climate.  We  have  a  continuous 
daily  record  for  one  hundred  years  at  New  Bedford, 
Massachusetts,  nearly  as  long  records  at  several 
other  places,  and  numerous  records  for  over  half  a 
century.  From  these  we  learn  that  there  has  been 
no  definite  change  in  climate  in  this  country  during 
the  past  hundred  years.  There  have  been  variations, 
such  as  an  excess  or  a  deficiency  of  rainfall  over  a 
considerable  area,  that  have  persisted  for  several 
years  at  a  tune;  but  in  each  case  the  conditions 
would  ultimately  come  back  to  normal,  or  more 
often  to  an  extreme  of  the  opposite  tendency  to  what 
had  obtained  immediately  before.  In  sections  where 


HAS  OUR  CLIMATE  CHANGED? 

the  rainfall  in  bountiful  years  is  barely  sufficient 
for  good  crops,  the  people  hi  the  past  have  been 
prone  to  consider  that  the  amount  that  they  re- 
ceive during  the  periods  of  excess  is  that  which  nor- 
mally is  due  them,  and  thus  to  be  unprepared  for 
the  dry  periods  that  statistics  tell  us  must  certainly 
come.  The  matter  of  change  of  climate  is  most 
important  to  our  sub-arid  West,  —  to  the  western 
parts  of  Texas,  Oklahoma,  Kansas,  Nebraska,  and 
the  Dakotas.  Some  years  ago,  when  the  tide  of 
emigration  was  strong  into  these  regions,  there  were 
several  years  of  more  than  the  average  rainfall.  The 
coming  of  population  and  the  coming  of  extra  ram- 
fall  were  accidentally  coincident,  but  that  fact  was 
probably  responsible  for  the  popular  belief  that 
civilization  brings  an  increase  in  precipitation ;  that 
the  breaking  of  the  virgin  soil,  making  it  more  per- 
meable to  the  absorption  of  moisture ;  the  planting 
of  trees  and  the  growth  of  crops,  restricting  the 
run-off ;  the  roots  of  the  new  vegetable  life  drawing 
up  the  moisture  from  below  the  surface  of  the  ground 
and  transpiring  it  to  the  air  through  the  leaves  of 
plants;  the  enormous  quantities  of  water  vapor 
ejected  into  the  air  by  the  combustion  necessarily 
incident  to  a  considerable  population,  —  all  had 
combined  to  increase  the  rainfall  and  render  the 


230  THE  NEW  AIR  WORLD 

sub-arid  plains  more  responsive  to  the  efforts  of 
the  husbandman.  No  one  can  fail  to  regret  that 
this  theory  is  not  founded  upon  fact.  But  a  mo- 
ment's thought  by  the  scientist  will  indicate  to  him 
that  the  volume  of  air  is  so  great,  and  under  the 
heat  of  the  growing  period  its  capacity  for  moisture 
so  enormous,  that  the  addition  of  vapor  of  water  by 
the  processes  herein  described,  great  though  it  be, 
is  ineffectual  to  appreciably  change  the  amount  of 
the  rainfall  that  nature  beforehand  had  ordained 
should  be  precipitated. 

The  size  of  continental  areas,  the  height  and  the 
trend  of  mountain  ranges,  the  proximity  of  large 
bodies  of  water,  and  the  direction  of  the  prevailing 
winds  are  the  factors  that  determine  the  amount 
of  the  precipitation  of  a  region.  Against  these  the 
puny  efforts  of  man,  stupendous  though  we  think 
them  to  be,  are  entirely  unavailing.  As  an  illustra- 
tion :  If  the  Rocky  Mountains  were  as  old  as  the 
Appalachian  Chain,  and  if  they  were  eroded  down  to 
the  height  of  the  latter  system,  the  winds  from  the 
Pacific  Ocean,  when  they  are  drawn  inland  by  the 
cyclonic  storms  of  the  Rocky  Mountain  plateau,  or 
of  the  Mississippi  Valley,  instead  of  depositing  their 
moisture  on  the  west  slopes  of  the  first  range  of 
mountains,  would  carry  the  water  vapor  of  the 


HAS  OUR  CLIMATE   CHANGED?     231 

Pacific  clear  to  that  place  in  the  Mississippi  Valley 
where  it  would  meet  the  moisture  drawn  by  the  same 
storms  from  the  Gulf  of  Mexico  and  the  Atlantic 
Ocean.  This  will  appear  clear  when  one  under- 
stands that  cyclonic  storms,  such  as  are  continually 
passing  across  our  continent  in  periods  of  about 
three  days  each,  may  embrace  in  their  eddy-like 
circulating  systems  areas  one  to  three  thousand 
miles  in  diameter,  in  which  the  winds  from  all  di- 
rections spirally  flow  towards  the  center  of  the 
cyclonic  system  and  the  system  itself  is  moving 
eastward. 

The  water  vapor  exists  as  a  separate  atmosphere 
from  oxygen  and  nitrogen.  It  is  screened  off  from 
the  interior  of  continents  by  mountain  ranges  be- 
cause it  is  condensed  and  precipitated  as  rain  or 
snow  at  only  moderate  elevations.  The  windward 
side  of  mountains  may,  therefore,  receive  torrential 
rains  while  their  leeward  sides  are  entirely  with- 
out precipitation. 

It  follows  that  if  the  Rocky  Mountains  were  low- 
ered as  described,  the  entire  United  States  would 
be  green  with  rich  vegetation  and  there  would  be  no 
deserts  anywhere  within  its  broad  boundaries. 
Also,  if  the  Appalachian  Range  were  as  high  as  the 
Rocky  Mountains  —  as  it  may  have  been  at  one 


232  THE  NEW  AIR  WORLD 

time  —  and  if  it  extended  around  the  Gulf  of  Mexico 
as  well  as  up  through  our  Atlantic  Coast  States,  the 
vaporous  atmosphere  of  the  Atlantic  Ocean  and  of 
the  Gulf  of  Mexico  would  be  prevented  from  enter- 
ing the  interior  of  the  continent,  and  the  power 
that  to-day  stands  as  the  greatest  bulwark  of  civi- 
lization would  not  exist.  There  would  be  but  a 
narrow  fringe  of  vegetation  upon  its  east  and  its 
west  coasts;  the  interior,  with  its  vast  cotton  and 
cereal  plains,  would  be  a  barren  waste. 

But  to  revert  for  a  moment  to  Jefferson.  He 
took  his  thermometer  to  Philadelphia  when  he 
proceeded  there  on  a  mission  that  would  have  caused 
any  less  serene  and  courageous  spirit  to  forget  all 
the  small  details  of  life.  When  the  debates  upon 
which  hung  the  fate  of  a  nation  and,  in  fact,  the 
lives  of  those  that  participated,  were  in  progress,  he 
coolly  hung  his  thermometer  on  the  wall  and  noted 
down  its  readings.  Those  historians  who  have 
described  the  intense  heat  in  Independence  Hall 
on  the  Fourth  of  July,  1776,  were  mistaken,  as  will 
be  shown  by  reference  to  his  observations,  the 
early  and  the  late  ones  of  which  doubtless  were  made 
at  his  lodgings.  They  are  as  follows :  6  A.M.,  68° ; 
9  A.M.,  72i° ;  1  P.M.,  76° ;  and  9  P.M.,  73^°. 

Jefferson  had  one  of  the  only  two  barometers  in 


HAS  OUR  CLIMATE  CHANGED?     233 

this  country  at  that  time.  James  Madison  (the 
Bishop,  not  the  President)  had  the  other.  They 
took  readings  at  the  same  hour  of  the  day  for  a  con- 
siderable period  of  time,  and  Jefferson  discovered 
that  changes  in  the  pressure  of  the  air  always  began 
on  his  instrument  a  few  hours  before  they  did  on 
his  friend's  instrument  a  couple  of  hundred  miles  to 
the  east  of  him.  He  came  near  discovering  the 
fact  that  no  matter  what  the  direction  of  the  wind, 
storms  almost  universally  move  from  the  west 
toward  the  east.  When  the  British  captured  Wash- 
ington they  also  raided  Monticello,  Jefferson's  home 
in  Virginia,  and  they  destroyed  his  barometer.  It 
has  been  said  that  he  was  as  much  distressed  over 
the  loss  of  his  special  instrument  of  science  as  he 
was  over  the  burning  of  the  National  Capitol. 

In  "Descriptive  Meteorology"  (Appleton),  the 
writer  expressed  doubt  that  there  had  been  important 
changes  in  climate  within  the  period  of  authentic 
history,  but  recent  researches  cause  him  to  change 
his  opinion,  for  the  evidence  now  seems  almost 
conclusive  that  marked  changes  have  occurred.  The 
powerful  kingdoms  of  Sumeria,  Babylonia,  Assyria, 
and  Persia,  each  ruling  many  centuries  and  domi- 
nating all  or  a  large  part  of  the  vast  region  from  the 
Persian  Gulf  to  the  Caspian  Sea  and  westward  to 


234  THE  NEW  AIR  WORLD 

the  Mediterranean  and  Egypt,  covering  in  their 
various  reigns  some  four  thousand  years  before  Christ, 
could  hardly  have  built  their  many  great  cities, 
supported  their  numerous  millions  of  population, 
and  developed  the  trade  and  commerce  that  was 
theirs  with  the  climatic  conditions  as  they  exist 
to-day.  As  late  as  the  opening  of  the  Christian 
Era,  Palmyra,  in  Syria,  had  a  population  of  from  one 
hundred  and  fifty  thousand  to  two  hundred  thousand 
people,  was  opulent  and  adorned  with  a  compara- 
tively high  civilization.  To-day  we  see  the  wreck- 
age of  its  vast  aqueduct  and  irrigating  systems, 
which  are  unable  to  gather  enough  water  to  wet 
their  well-constructed  walls,  and  a  few  hundred 
people  eke  out  a  miserable  existence  where  once 
was  a  metropolis  teeming  with  life  under  luxurious 
conditions.  The  same  picture  is  shown  in  more  or 
less  relief  throughout  the  greater  part  of  the  region 
that  once  maintained  the  greatest  empires  of  antiq- 
uity. But  we  must  not  assume  that  such  dry  and 
nearly  barren  conditions  are  to  continue  forever; 
rather  are  we  to  imagine  that  within  a  cycle  of  a  few 
thousand  years  this  region  may  have  a  rebirth  of 
abundant  vegetation  and  again  throb  with  the 
pulsations  of  abounding  life. 

The  record  inscribed  by  the  waters  on  the  aban- 


HAS  OUR  CLIMATE   CHANGED?      235 

doned  and  the  submerged  shores  of  inland  lakes 
and  seas  in  the  Rocky  Mountains,  and  on  the  shores 
of  the  Caspian  Sea  and  other  waters,  is  easy  to  read. 
It  shows  several  great  oscillations  of  climate  in  the 
United  States  and  the  most  civilized  portions  of 
the  world  since  the  birth  of  Christ.  For  some 
time  before  and  for  several  centuries  after  the  begin- 
ning of  our  era  there  was  a  wet  period.  The  Caspian 
Sea  stood  some  one  hundred  feet  higher  than  now 
and  an  abandoned  beach  and  a  clearly  marked 
shore  line  show  that  Lake  Owens,  in  California,  on 
the  east  side  of  the  Sierras,  existed  at  a  level  nearly 
two  hundred  feet  higher  than  now.  There  was  an 
abundance  of  water  to  irrigate  the  Holy  Land,  and 
although  the  center  of  dominating  human  power 
had  long  since  passed  in  succession  Babylon,  Assyria, 
Persia,  Greece,  Macedon,  and  was  working  its  way 
towards  the  Atlantic,  the  Mesopotamian  Valley  was 
abundantly  fruitful. 

Then,  for  six  or  seven  hundred  years,  with  short- 
period  variations  of  from  thirty  to  fifty  years,  the 
world  inhabited  by  civilized  man  and  large  areas 
in  the  temperate  zone  not  yet  civilized,  grew  drier. 
The  Caspian  Sea  fell  to  a  lower  level  than  it  now 
maintains,  for  the  ends  of  great  walls,  constructed 
to  keep  out  barbarians,  and  other  evidences  of  the 


236  THE  NEW  AIR  WORLD 

handiwork  of  man,  are  now  many  feet  below  the 
surface  of  the  water.  This  is  the  driest  time  known 
to  history.  Ellsworth  Huntington  of  Yale,  acting 
under  the  auspices  of  the  Carnegie  Foundation  at 
Washington,  made  an  examination  of  many  of  the 
stumps  of  the  big  trees  of  California,  ranging  in  age 
from  one  to  four  thousand  years.  The  thickness 
of  each  ring  of  annual  growth  is  a  legible  record  of 
the  wetness  or  the  dryness  of  the  year.  One  would 
hardly  think  of  these  towering  giants  of  the  floral 
kingdom  as  being  both  thermometers  and  rain 
gauges,  accurately  measuring  and  recording  the 
dry-hot  and  the  wet-cold  periods  for  thousands  of 
years,  and  now  at  the  end  of  their  majestic  careers 
revealing  the  hidden  secrets  of  past  ages.  Hunt- 
ington and  Cushing,  in  "  Principles  of  Human  Geog- 
raphy", say : 

"  The  rings  dating  from  the  time  of  Christ  are 
thick  and  indicate  that  at  that  time,  when  Palmyra 
had  an  abundant  supply  of  water,  when  Owens 
Lake  overflowed  and  there  was  high  water  in  the 
Caspian  Sea,  the  big  trees  also  had  plenty  of  water 
and  grew  rapidly.  Six  or  seven  hundred  years 
later,  when  Palmyra  was  abandoned  and  when  the 
Caspian  Sea  stood  fifteen  or  twenty  feet  lower  than 
at  present,  the  trees  formed  only  narrow  rings, 
because  the  climate  was  dry.  The  way  in  which 


HAS  OUR  CLIMATE  CHANGED?     237 

the  growth  of  the  trees  has  varied  is  shown  in  Figure 
30.  The  high  part  of  the  curve  indicates  abundant 
rainfall.  The  black  shading  at  the  bottom  indicates 
periods  of  comparative  aridity." 


TOO    200ao0400500€OOr00800900IOOOMOO«200000MOOBOO  KOO  1700  MOO  1900 


FIG.  30.  —  Changes  in  Climate  in  California  during  the  Christian  Era. 
Black  shading  indicates  Drought. 

Since  the  extensive  system  of  observations  by  the 
Weather  Bureau  was  inaugurated,  some  fifty  years 
ago,  it  has  been  revealed  to  us  that  frequently  the 
Ohio  Valley  would  suffer  a  deficit  in  rainfall  that 
would  persist  for  periods  as  great  as  five  or  six  years, 
while  New  England  and  the  South  Atlantic  States, 
or  other  large  areas  of  the  country,  had  an  excess. 
This  is  an  illustration  that  excesses  in  one  part  of  the 
country  were  balanced  by  shortages  in  other  parts 
that  occurred  at  the  same  time.  But  the  long- 
period  oscillations  in  climate  that  are  measured  in 
hundreds  of  years  instead  of  tens  —  these  changes 
seemed  to  have  occurred  simultaneously  in  the 
middle  latitudes  of  Europe  and  America.  These 
changes  were  simultaneous  in  an  east  and  west 
direction.  Now  we  have  evidence  of  such  long-period 


238  THE  NEW  AIR  WORLD 

changes  in  a  north  and  south  direction  which  were 
simultaneous,  but  of  an  opposite  character,  indicating 
that  during  the  Christian  Era  the  eastward  track  of 
storms  has  oscillated  northward  and  southward. 
This  would  account  for  the  occurrence  of  dry  and  of 
wet  periods  simultaneously  throughout  the  vast 
stretch  of  territory  between  southern  California  and 
the  Caspian  Sea.  In  Guatemala,  Yucatan,  and  other 
Central  American  countries  there  are  ruins  of  cities 
and  the  evidence  of  an  agriculture  and  a  civilization 
that  could  not  have  been  established  with  the 
torrential  rains  and  jungle  growths  that  now  prevail 
in  those  regions.  During  the  centuries  when  the 
big  trees  of  California  were  receiving  a  large  rainfall 
and  making  a  thick  annual  growth,  especially  about 
the  beginning  of  the  Christian  Era,  because  of  a 
northward  shifting  of  the  climatic  zone,  the  precipi- 
tation in  Yucatan  and  Guatemala  had  so  diminished 
as  to  leave  only  the  amount  of  rainfall  that  could  be 
economically  employed  in  agriculture  and  in  the 
rearing  of  great  cities ;  and  then,  with  a  southward 
migration  of  the  rain  belt,  these  cities  were  suffocated 
with  excessive  precipitation,  agriculture  rendered 
impossible,  and  their  temples  and  palaces  buried 
beneath  the  gloom  of  a  tropical  growth. 

If  we  are  to  reason  from  the  records  of  the  past 


HAS  OUR   CLIMATE   CHANGED?     239 

it  seems  highly  probable  that  at  least  the  middle 
latitudes  of  the  Northern  Hemisphere  are  slowly 
passing  out  of  a  dry  period  that  has  prevailed  for 
the  past  two  hundred  years  or  more.  For  several 
hundred  years  all  the  great  glaciers  have  receded, 
but  we  should  not  expect  such  recession  to  continue 
indefinitely.  Geology  furnishes  abundant  evidence 
that  great  changes  took  place  in  the  climate  of  the 
earth  during  the  prehistoric  ages;  that  there  were 
several  glacial  periods,  the  last  occurring  during 
pleistocene  times,  somewhere  between  twenty  and 
fifty  thousand  years  ago,  and  that  there  were  inter- 
vals between  the  culminations  of  the  Ice  Ages  of  prob- 
ably fifty  thousand  to  one  hundred  thousand  years. 
Between  these  long  winters,  that  have  meant  death 
and  desolation  to  much  of  what  are  now  the  most 
civilized  portions  of  the  earth,  there  have  been  warm 
periods  of  thousands  of  years'  duration. 

Fossil  remains  show  that  regions  far  north,  now 
covered  with  perpetual  ice,  once  supported  a  luxuri- 
ant flora  and  fauna,  and  many  regions  in  the  tem- 
perate and  equatorial  zones  that  are  now  deserts 
were  once  overgrown  with  forests  and  teeming 
with  animal  life.  The  fundamental  thing  of  the 
cosmos  is  change  —  birth,  growth,  maturity;  then 
decline,  senility,  death,  decay,  disintegration;  and 


240  THE  NEW  AIR  WORLD 

always  a  renaissance,  or  new  birth.  Energy  and 
life  seem  to  be  eternal,  but  ever  undergoing  change. 
The  Great  Ice  Cap  may  again  cover  New  England, 
the  region  of  the  Great  Lakes,  and  flow  southward 
to  the  Ohio  River,  but  the  change  will  be  so  gradual, 
if  it  does  come,  that  there  will  be  no  great  cities  to 
be  ground  beneath  the  feet  of  the  boreal  monster; 
cold  that  will  precede  the  ice  cap  will  destroy  them 
and  they  will  be  buried  beneath  the  dust  of  ac- 
cumulating ages  before  their  icy  tombstone  is  erected. 
Then  the  healthful  and  invigorating  climate  of  the 
north  part  of  our  country  will  be  transferred  to  the 
region  of  the  Gulf  of  Mexico.  Civilization  will  and 
must  migrate  with  the  shifting  of  the  climatic  belts. 
Because  these  changes  cannot  possibly  concern  us 
personally,  we  have  almost  neglected  the  study  of 
the  great  forces  that  silently  yet  most  persistently 
are  at  work  altering  the  conditions  under  which 
future  man  must  live  and  work  out  the  destiny  of 
coming  generations. 

Effects  of  Forests  on  Climate  and  Floods.  Next  to 
the  fallacious  belief  in  a  change  of  climate  during 
the  life  of  an  individual  there  are  few  if  any  errors 
that  have  gained  such  wide  acceptance  as  a  belief  that 
the  cutting  away  of  the  forests  has  caused  a  marked 
change  in  climate  and  especially  in  the  frequency 


HAS  OUR  CLIMATE   CHANGED?     241 

and  intensity  of  floods  and  droughts.  The  writer 
shared  in  the  mistake  with  regard  to  the  influence 
of  the  forests  in  restraining  run-off  and  augmenting 
floods,  until  compelled  by  an  order  of  the  Congress 
of  the  United  States  to  prepare  a  report  on  the  floods 
of  the  nation  that  had  occurred  during  the  time  of 
the  gradual  reduction  of  the  forest  areas.  Dividing 
into  two  equal  periods  the  forty  years  for  which 
the  Weather  Bureau  has  comprehensive  records  of 
the  rainfall  upon  the  catchment  basins  of  the  Ten- 
nessee, the  Cumberland,  and  the  Ohio  rivers,  and 
for  which  it  has  records  of  the  height  of  the  rivers, 
contrary  to  his  belief,  he  found  that  the  high  waters 
were  no  higher  with  a  given  rainfall,  the  floods  of 
no  longer  duration,  nor  the  low  waters  of  summer 
lower,  during  the  last  half  of  the  period  than  during 
the  first  half. 

It  is  now  pretty  generally  conceded  by  hydraulic 
engineers  that  the  broken,  permeable  soil  of  the 
husbandman,  frequently  stirred  by  cultivation  a 
part  of  the  year  and  filled  with  countless  billions  of 
the  tiny  water-absorbing  rootlets  of  the  grasses 
and  the  cereal  crops  during  the  remainder  of  the 
annual  period,  is  equally  as  good  a  conserver  of  the 
rainfall  as  the  forests  themselves,  even  if  it  is  not 
better. 


THE  NEW  AIR  WORLD 

Some  years  ago  the  writer  was  delivering  a  series 
of  Chautauqua  lectures.  He  arrived  at  Devil's 
Lake,  North  Dakota,  and  found  that  the  Chautauqua 
amphitheater  was  on  the  banks  of  Devil's  Lake, 
once  bordering  the  town,  but  now  receded  to  a  dis- 
tance of  five  miles  and  confined  to  a  narrow  valley. 
In  driving  from  the  city  to  the  lecture  hall  he  re- 
marked to  his  escort  that  they  seemed  to  be  travel- 
ing along  the  bottom  of  an  ancient  lake.  His  com- 
panion said,  "  Yes,  a  lake,  but  not  an  ancient  one. 
Fifty  years  ago  I  used  to  dive  off  a  springboard  right 
there  in  front  of  the  railroad  station."  In  the 
course  of  his  lecture  the  writer  referred  to  this  inci- 
dent and  told  them  that,  contrary  to  their  belief, 
their  climate  had  not  changed,  that  fifty  years  ago 
they  sold  their  old  lake  to  some  gentlemen  in  Chicago 
and  that  they  had  been  selling  it  over  again  every 
year  since;  that  the  former  compact  surface  of  the 
virgin  prairie  resisted  the  penetration  of  the  rain- 
fall, or  at  least  only  slowly  absorbed  it,  and  allowed 
it  to  collect  in  the  depression  adjacent  to  the  city ; 
but  now,  in  the  broken,  permeable  soil  of  the  farmer 
it  was  taken  up  by  millions  of  tiny  rootlets  and  the 
hand  of  the  Great  Alchemist  had  transformed  their 
lake  into  wheat,  the  sale  of  which  was  responsible 
for  the  presence  of  the  speaker  on  the  platform  of  a 


HAS  OUR  CLIMATE  CHANGED?     243 

largely-attended  Chautauqua.  The  lake  had  gone 
never  to  return  unless  the  region  were  again  to  be- 
come the  haunt  of  the  buffalo  and  the  prairie  dog 
instead  of  civilized  man.  The  rainfall  was  the  same, 
but  it  was  now  being  utilized  for  the  benefit  of  man- 
kind. 

In  this  problem  of  rainfall,  floods,  and  the  forests, 
most  persons  assume  that  when  the  forest  is  cut 
the  land  is  at  once  denuded  of  vegetation.  On  the 
other  hand  a  second  growth  will  effectually  shade 
the  soil  within  a  few  months  or  a  few  weeks  after 
the  large  trees  are  removed,  and  if  the  land  is  cleared 
and  rendered  fit  for  the  plow,  growing  crops  take 
the  place  of  the  forest-covering  the  greater  portion 
of  the  time. 

There  is  an  abundance  of  reasons  for  the  protection 
of  our  diminishing  forests  and  for  the  creation  of 
new  forest  areas  without  assigning  to  the  forests 
functions  that  they  do  not  exercise.  The  covering 
of  an  area  by  a  great  city,  a  village,  a  forest,  a  barn, 
or  a  tent  modifies  the  climate  of  the  particular  area 
covered  so  long  as  the  covering  remains,  but  there  is 
no  appreciable  climatic  effect  a  few  feet  above  the 
surface  of  the  earth  between  a  forest  and  a  field  of 
grain.  The  climate  of  a  region  like  the  American 
continent  is  controlled  fundamentally  by  the  great 


244  THE  NEW  AIR  WORLD 

oceans  that  wash  its  shores,  by  the  trend  of  its  moun- 
tain systems  and  their  height,  and  by  the  direction 
of  its  prevailing  winds.  The  vast  vaporous  atmos- 
phere that  flows  inland  from  the  Atlantic  Ocean 
to  the  foothills  of  the  Rocky  Mountains,  deluging 
our  cereal  plains  with  its  life-giving  precipitation 
will  continue  its  pluvial  generosity  without  any  heed 
whatever  to  the  puny  scratchings  of  man  upon  the 
surface  of  Mother  Earth.  Nothing  that  man  can 
do  will  intensify  drought  conditions  on  this  conti- 
nent or  augment  the  volume  of  floods.  It  is  time 
that  we  return  to  sanity  in  considering  this  mat- 
ter instead  of  being  frightened  by  the  dire  forebodings 
of  well-meaning  but  purely  visionary  enthusiasts,  no 
matter  how  noble  their  aspirations  may  be  or  how 
self-sacrificingly  they  have  consecrated  themselves 
to  the  redemption  of  humanity. 

It  is  certain  that  forests  restrict  the  flow  of  mod- 
erate falls  of  rain,  but  they  do  not  restrain  the  flow  of 
flood  waters,  because,  surprising  as  it  may  seem  to 
one  who  has  not  tested  the  matter,  floods  do  not 
occur  until  after  all  surfaces,  open  fields  and  forests 
alike,  have  become  saturated,  and  then  the  run-off  of 
the  two  surfaces  is  equal. 


CHAPTER  XIV 
CLIMATES  FOR  HEALTH  AND  PLEASURE 

ONE'S  LIFE  WOULD  BE  PROLONGED  IF,  LIKE  THE  BIRDS, 
ONE  COULD  MIGRATE  ANNUALLY  WITH  THE  TEM- 
PERATURE —  CHRISTMAS  IN  MANY  CLIMES  THE 

HOTTEST  AND   COLDEST   PLACES  IN  THE  WORLD 

FROM  what  has  gone  before  it  is  apparent  that 
the  regions  of  the  earth  where  man  is  at  his  best 
estate,  so  far  as  climate  can  determine  his  environ- 
ment, may  be  broadly  defined  in  this  country  as 
southern  New  England,  southern  and  central  New 
York,  the  Middle  Atlantic  States,  the  Ohio  Valley, 
the  southern  Lake  Region  and  westward  to  the  middle 
of  Kansas  and  Nebraska ;  in  Europe  it  includes  the 
British  Isles,  France,  Switzerland,  extreme  northern 
Italy,  Austria,  Germany,  Belgium,  Holland,  and 
the  extreme  southern  parts  of  Norway  and  Sweden. 
But  in  none  of  these  regions  is  the  climate  equally 
good  during  all  seasons.  In  fact  there  are  two  short 
seasons  in  each  year  when  it  is  debilitating. 

The   great   majority   of   the   people,   like   galley 


246  THE  NEW  AIR  WORLD 

slaves  chained  to  their  oars,  must  remain  in  the 
same  place  throughout  the  year,  others  may  have  a 
vacation  of  several  weeks,  and  still  others  are  free 
to  change  their  location  as  often  as  fancy  calls  them. 
The  latter  might  well  learn  from  the  birds,  and  by 
migrating  with  the  temperature,  going  far  north 
in  summer  and  far  south  in  winter,  maintain  them- 
selves throughout  the  entire  year  in  the  most  per- 
fect atmospheric  conditions  for  health,  happiness, 
and  long  life.  Many  a  man  of  fifty,  having  ac- 
cumulated enough  to  modestly  supply  his  wants, 
could  add  ten  to  thirty  years  to  his  life,  or  might 
even  double  the  period  of  his  existence,  by  ceasing 
to  strive  after  riches,  and  by  giving  himself  up  to  a 
healthful  movement  about  this  beautiful  world.  His 
principal  companions  should  be  good  books,  —  the 
study  of  which  will  enlarge  his  mental  horizon  and 
increase  his  capacity  to  see,  comprehend,  and  enjoy, 
and  fit  him  to  speak,  act,  and  think  in  ways  that  will 
inure  to  the  public  good.  If  he  has  not  had  the 
benefits  of  a  college  education,  now  is  the  golden 
opportunity  to  read,  and  have  pleasure  in  the  read- 
ing, popular  books  on  Geology,  Botany,  Biology,  As- 
tronomy, and  Physics,  and  to  become  familiar  with 
the  history  of  his  own  country  and  of  the  world. 
It  need  not  be  a  period  of  idleness  but  one  of  beau- 


HEALTH  AND  PLEASURE  247 

tiful  growth  and  of  appreciation  of  the  wonders  of 
creation.  And  thus  will  his  spirit  be  lifted  up  and 
fitted  for  a  higher  realm  of  existence  in  the  world  to 
come. 

To  those  who  must  remain  at  home  during  heat 
spells,  the  advice  is  given  to  close  not  only  the 
shutters  but  the  windows  on  the  east  side  of  the 
house  during  the  forenoon  and  do  the  same  on  the 
west  side  in  the  afternoon.  The  best  night's  sleep 
will  be  gained  in  a  room  facing  north  on  any  floor 
that  is  not  next  the  roof ;  this  room  will  be  cooler  if 
it  is  protected  by  another  room  on  its  east  and  one 
on  its  west  side. 

Long  Life  in  the  Open  Air  and  the  Sunshine.  It 
is  difficult  to  decide  which  most  conduces  to  health 
and  longevity  :  cheerfulness  of  mind  and  kindness  of 
thought,  or  life  in  the  open  air  and  in  the  blessed 
sunshine.  If  one  can  enjoy  both  of  these  benefi- 
cent conditions  they  should  live  as  long  as  they 
desire  to  remain  on  earth.  Most  people  live  as  long 
as  they  deserve  to  live.  It  has  facetiously  been  said 
that  old  age  is  a  bad  habit.  The  writer  is  disposed 
to  agree  with  the  humorist.  Certain  it  is  that  few 
persons  who  believe  in  the  limitation  of  life  to  three 
score  and  ten  ever  live  beyond  that  period,  while 
one  should  be  possessed  of  a  sound  body  and  a  supe- 


248  THE  NEW  AIR  WORLD 

rior  mind  at  that  age,  with  just  anticipations  of  a 
third  of  a  century  of  usefulness  and  happiness  yet 
to  come.  As  a  man  thinketh,  so  is  he.  We  are 
just  beginning  to  comprehend  something  of  the 
wonderful  power  with  which  the  Creator  has  in- 
vested us  in  the  development  and  the  care  of  our 
bodies.  Anger,  hatred,  malice,  jealousy,  selfishness, 
fear,  and  worry  create  poisons  that  may  bring  on 
disease  and  death,  but  they  certainly  create  a  mor- 
bidity in  the  body  that  shortens  life. 

Sunshine  destroys  molds,  bacteria,  and  other 
enemies  of  the  human  race  that  lurk  in  the  darkness. 
It  strikes  dead  the  tubercle  bacillus,  which  is  such 
a  scourge  to  mankind.  Its  remedial  power  comes 
largely  from  invisible  light  —  the  ultra-violet  and  the 
supra-red  rays.  You  are  blind  to  these  rays  but 
your  skin  and  blood  are  not ;  they  need  the  sunshine 
to  give  them  vitality  —  not  quack  medicines  or 
medical  tonics  for  which,  through  the  venal  partner- 
ship of  the  Press,  millions  of  the  afflicted  are  induced 
not  only  to  part  with  the  money  so  much  needed  by 
their  families  and  themselves,  but  to  aggravate 
their  sufferings.  The  sunshine  of  a  high  region  is 
beneficial  to  those  ill  with  coughs,  colds,  bronchitis, 
tuberculosis,  anaemia,  or  other  wasting  diseases, 
because  the  upper  altitudes  are  rich  in  many  rays 


HEALTH  AND  PLEASURE  249 

that  are  beneficial,  some  of  which  are  absorbed  by 
the  higher  air  and  do  not  penetrate  to  the  earth,  or 
only  reach  the  earth  in  minute  quantities.  There 
on  the  mountain  the  sun's  rays  are  unpolluted  by  the 
dust  and  the  bacteria  of  lower  levels  and  the  cities. 
But  one  does  not  need  extreme  altitudes.  Two  to 
three  thousand  feet  may  be  sufficient. 

Mountain  and  Sea  Air  and  the  Injury  from  Over- 
bathing.  The  seashore  is  properly  a  great  national 
playground  during  the  heat  of  summer.  Evaporated 
spray  leaves  a  trace  of  salt  in  the  air  which,  with 
the  salt  of  the  ocean,  seems  to  be  beneficial  to  many. 
Likewise  there  is  no  condition  of  life  that  is  not  bene- 
fited by  the  pure  air  of  the  wooded  mountains. 
Those  of  moderate  vigor  may  build  up  and  maintain 
high  vitality  by  continuous  bathing  in  the  cool, 
pure  waters  of  mountain  lakes  and  streams,  but  to 
many  daily  swimming  in  either  fresh  or  salt  water, 
except  that  it  be  for  a  mere  dip  and  right  out  again, 
that  is  so  cold  as  to  be  painful  to  the  delicate  sen- 
sations of  the  skin,  is  extremely  debilitating  to  all 
bodily  functions.  Be  moderate. 

How  to  Find  the  Climate  You  Seek.  At  sea  level 
in  the  tropics  heat  and  moisture  combine  to  produce 
great  physical  discomfort.  But  even  under  the 
equator  it  is  possible  to  escape  the  tropical  heat  of 


250  THE  NEW  AIR  WORLD 

low  levels  by  ascending  four  to  six  thousand  feet, 
as  can  be  done  in  some  places  in  Porto  Rico  and 
Cuba.  Most  of  the  capitals  of  South  American 
countries  are  located  at  altitudes  of  five  to  ten  thou- 
sand feet;  and  Brazil  is  planning  to  abandon  her 
capital  at  sea  level  and  move  the  administrative 
machinery  of  government  from  the  splendid  city  of 
Rio  de  Janeiro  to  a  mountain  location  in  the  interior. 
Any  region  of  the  Alleghany  system  of  mountains 
above  a  thousand  feet  elevation  possesses  climatic 
conditions  of  therapeutic  value.  Illustration  of  this 
fact  is  seen  in  the  success  of  the  noted  sanitaria  in 
the  Adirondacks,  and  in  the  mountain  regions  of 
North  Carolina  and  Virginia,  and  in  the  northern 
part  of  New  England.  These  sections  are  especially 
frequented  by  persons  suffering  from  pulmonary 
diseases,  or  from  nervous  exhaustion,  many  of  whom 
find  not  only  relief  but  cure.  Cool  and  healthful 
conditions  of  temperature  may  be  found  during  the 
summer  along  the  ridges  and  on  the  peaks  of  the 
entire  mountain  system  that  extends  from  North 
Carolina  northward  through  Virginia,  Pennsylvania, 
New  York,  and  New  England.  The  advice  of  one's 
physician  should  be  sought,  if  one  is  ailing,  before 
determining  between  the  seashore  and  the  mountains, 
but  in  general  those  suffering  from  diseases  of  the 


HEALTH  AND  PLEASURE  251 

respiratory  organs  are  better  located  in  the  high 
levels,  remote  from  the  humid  air  of  the  ocean. 

In  winter  Bermuda,  Florida,  Porto  E-ico,  Cuba, 
the  southern  part  of  the  Gulf  States,  much  of  South- 
ern California,  and  Hawaii  have  balmy  climates 
that  permit  of  outdoor  life  without  temperatures 
too  high  to  be  comfortable.  Hawaii  and  Bermuda 
have  mild  climates  not  only  during  winter  but 
throughout  the  entire  year.  The  Riviera  on  the 
Gulf  of  Genoa  and  the  beautiful  Lake  region  of 
Italy  enjoy  the  balmy  air  of  the  Mediterranean  and 
are  protected  from  the  cold  winter  winds  by  the 
Alps. 

From  October  to  May  that  portion  of  the  Rocky 
Mountain  plateau  that  includes  Arizona,  New 
Mexico,  and  the  northern  interior  of  Old  Mexico 
has  one  of  the  finest  climates  in  the  world  for  those 
afflicted  with  pulmonary  diseases,  as  the  sunshine 
is  abundant  and  the  day  and  night  temperatures 
such  as  to  permit  an  almost  continuous  out-of- 
doors  existence.  But  the  heat  and  the  extreme  dry- 
ness  of  the  air  in  June,  July,  August,  and  the  first 
half  of  September  is  irritating  to  the  nerves  and 
debilitating  in  general.  Fortunately,  when  the  con- 
ditions are  not  favorable  in  the  extreme  southwest 
part  of  the  country,  they  are  at  their  best  in  the 


252  THE  NEW  AIR  WORLD 

mountains  of  the  Middle  Atlantic  States  and  New 
England,  which  offer  to  the  pleasure  or  the  health 
seeker  a  cool,  pure  air  unsurpassed  by  any  other 
region  of  the  earth. 

For  an  all-the-year  climate  for  the  health  seeker, 
it  only  can  be  said  that  the  ideal  conditions  do  not 
continue  at  any  place  throughout  the  entire  year. 
Possibly  it  is  well  that  it  is  so,  as  a  change  may  be 
beneficial  for  no  reason  except  that  it  is  a  change. 
There  is  one  great  caution  ever  to  be  borne  in  mind, 
and  that  is  that  the  health  seeker  must  not  con- 
tinue or  repeat  the  same  unhygienic  life  in  his  new 
climate  that  brought  on  the  disease  in  the  old. 

Climate  of  Cuba.  The  climate  of  one  tropical 
country  may  differ  materially  from  that  of  another 
in  the  same  latitude  as  a  result  of  difference  in 
altitude,  proximity  to  large  bodies  of  water,  and 
position  with  respect  to  the  prevailing  winds.  Cuba 
being  in  the  region  of  the  northeast  trade  winds, 
more  rain  falls  on  the  north  side  of  its  mountains  than 
on  the  south  side.  The  temperature  of  the  south- 
east coast  is  higher  than  it  is  on  the  northern  and 
western  coasts,  and  the  range  of  temperature  every- 
where between  night  and  day  is  small,  rarely  ten 
degrees  and  usually  much  less.  It  therefore  has  a 
warm,  humid,  and  monotonous  climate,  except  in 


HEALTH  AND   PLEASURE  253 

the  high  levels  of  its  mountains.  The  winter  tour- 
ist will  find  the  conditions  of  the  greater  part  of  the 
island  somewhat  similar  to  those  in  the  region  of 
Miami,  Florida,  but  warmer.  Havana  is  not  so  hot  as 
Santiago.  The  highest  temperature  ever  recorded  at 
Havana  is  101°  and  the  lowest  50°.  A  fairly  pleasant 
temperature  always  can  be  found  within  a  short  ride 
to  the  mountains.  As  in  most  tropical  countries, 
Cuba  has  a  dry  and  a  wet  season.  The  rainy  season 
is  May  to  October.  In  the  early  part  of  September, 
1900,  over  thirty-six  inches  of  rain  fell  within  thirty- 
six  hours  at  Santiago.  As  a  rule  the  precipitation  is 
in  the  shape  of  heavy  showers,  the  clouds  clearing 
as  soon  as  the  rain  ceases;  the  showers  usually 
occur  in  the  afternoon.  Cuba,  in  common  with 
all  the  islands  of  the  West  Indies,  occasionally  is 
visited  by  destructive  hurricanes;  these  storms 
mainly  are  confined  to  the  period  August  to  October. 
Frequent  terrific  thunderstorms  occur  in  summer. 

Climate  of  Porto  Rico.  Its  mountainous  character 
gives  it  a  marked  diversity  of  climate,  torrential 
rains  falling  on  the  windward  side  of  its  mountains, 
while  the  leeward  sides  are  comparatively  dry.  The 
highest  temperature  in  San  Juan  since  1876  is  101° 
and  the  lowest  57°.  In  this  city  a  cool  breeze,  known 
as  the  "  briza",  adds  to  the  comfort  of  the  late 


254  THE  NEW  AIR  WORLD 

afternoon  and  evening.  The  wet  season  begins  a 
month  earlier  than  in  Cuba  and  lasts  a  month 
longer.  San  Juan  is  probably  the  most  healthful 
city  in  the  West  Indies,  but  those  reared  in  north- 
ern climates  invariably  suffer  from  its  enervating 
influence  after  several  years  of  continuous  residence. 
Water  is  abundant,  there  being  some  seventy  rivers 
and  over  a  thousand  small  streams.  The  moun- 
tains are  clothed  in  vegetation  to  their  tops,  and 
frost  of  a  killing  nature  is  practically  unknown  in  the 
island. 

Climate  of  the  Hawaiian  Islands.  Much  has 
been  written  about  the  charm  of  the  Hawaiian 
Islands,  their  mountains,  volcanoes,  tropical  verdure, 
and  delightful  climate.  It  is  indeed  a  garden  spot, 
and  its  soil  and  climate  make  it  so.  Nowhere  in 
the  islands  does  the  temperature  reach  90°  at  any 
time  of  the  year,  while  at  Honolulu,  the  largest  city 
and  the  capital,  a  temperature  lower  than  60°  is 
rarely  experienced.  Of  course,  as  one  ascends  the 
high  mountains  for  which  the  group  is  noted,  much 
lower  temperatures  are  encountered,  while  snow  is 
not  infrequent  near  the  tops.  July  and  August 
are  the  warmest  months  and  January  the  coldest. 
The  climate  is  soothing  and  dreamy  and  doubtless 
would  prolong  the  life  of  many  who  are  aged  and 


HEALTH  AND  PLEASURE  255 

slowly  passing  to  their  end,  and  that  of  others  of 
low  vitality  but  no  organic  disease.  Most  of  the 
rain  falls  November  to  May,  but  some  falls  in  every 
month  of  the  year.  At  Honolulu  the  amount  is 
about  that  which  falls  in  Wisconsin,  but  at  a  station 
in  the  Kohala  Mountains  one  hundred  and  fifty-four 
inches  have  been  measured  as  the  rainfall  for  seven 
months,  and  forty-two  inches  for  one  month,  the 
latter  being  a  larger  amount  than  the  annual  rain- 
fall for  the  State  of  Iowa. 

Climate  of  the  Philippines.  The  highest  tempera- 
ture so  far  recorded  at  Manila  is  100°  and  the  lowest 
60°.  It  is  therefore  warmer  than  either  Havana 
or  Porto  Rico.  The  hottest  months  are  April, 
May,  and  June,  but  the  cool  months  are  but  a  trifle 
cooler  than  the  warm  months,  the  annual  range  of 
temperature  being  but  three  degrees.  The  humidity 
is  high  at  all  seasons,  and  therefore  the  heat  is  op- 
pressive and  debilitating.  The  greater  part  of  the 
rainfall  of  Manila  is  from  June  to  October.  Some 
relief  may  be  gained  from  the  low-level  heat  by  re- 
treat to  the  mountains  of  some  of  the  islands.  It 
will  require  several  generations  before  the  white 
man  can  become  acclimated  to  this  region.  The 
islands  lie  between  latitude  6°  and  18°  North.  White 
children  born  of  American  parents  and  raised 


256  THE  NEW  AIR  WORLD 

there  never  will  have  the  energy  or  ambition  of 
their  progenitors.  If  it  were  not  for  the  invig- 
orating air  of  the  mountain  resort  at  Baquio, 
many  American  officials  could  not  continue  a  resi- 
dence in  the  Philippines. 

Climate  of  Bermuda  in  Comparison  with  the 
Popular  Winter  Resorts  of  Florida  and  California. 
It  is  a  mistake  to  represent  the  climate  of  Ber- 
muda as  one  of  balmy  sunshine  during  winter 
months.  It  has  some  glorious  days,  but  a  large  pro- 
portion are  cloudy,  rainy,  cool,  and  windy,  and  too 
cold  for  comfortable  or  healthful  bathing  from  the 
middle  of  December  to  the  first  of  May.  And  yet, 
its  climate  is  healthful  as  a  whole  for  nine  months  of 
the  year  and  more  stimulating  than  is  that  of 
Florida  in  winter.  If  one  wishes  sunshine  and  sea 
bathing  in  midwinter,  it  is  better  to  go  to  Palm 
Beach,  St.  Petersburg,  or  Miami,  Florida ;  but  if  one 
desires  to  have  a  moderately  cool  climate  with  a 
temperature  of  but  little  variation  between  midday 
and  midnight,  and  occasionally  a  day  with  sufficient 
warmth  and  sunshine  to  justify  a  dip  in  the 
ocean  or  in  the  many  land-locked  bays  with  which 
the  islands  abound,  one  well  may  come  to  Bermuda. 
Such  winter  clothing  as  one  naturally  would  wear  in 
Philadelphia  or  Washington  is  what  one  will  need  in 


HEALTH  AND  PLEASURE  257 

order  to  be  comfortable.  Bermuda  is  no  place  for 
Palm  Beach  suits,  outing  shirts,  and  Panama  hats 
in  winter.  Many  tourists  are  mislead  by  the  adver- 
tisements of  steamship  lines  and  bring  clothing 
which  is  suitable  only  for  early  fall  and  late 
spring. 

From  the  first  of  November  to  the  middle  of  May 
the  author  occupied  a  room  on  the  ground  floor, 
facing  the  waters  of  Hamilton  Harbor,  and  only 
fifty  feet  from  the  shore  line.  Here  the  diurnal 
range  of  temperature  is  much  less  than  at  Prospect 
Hill,  where  the  Government's  observations  are  made. 
From  the  middle  of  December  to  the  middle  of  March, 
a  thermometer  in  this  room  sluggishly  ranged  from 
60°  at  night  to  64°  during  the  day,  and  days  when  the 
wind  was  high  and  rain  falling  —  as  occurs  about 
one  third  of  the  time  in  winter  —  the  thermometer 
would  not  vary  a  degree  from  60°  during  the  entire 
twenty-four  hours.  During  April  the  range  each 
day  was  from  68°  at  night  to  70°  at  midday,  and 
during  November  and  May  from  70°  to  76°. 

The  selection  of  the  best  winter  climate  for  health 
and  for  pleasure  is  so  important  that  comparative 
data  are  here  given  of  the  most  popular  places  that 
are  easy  of  access  to  the  people  of  the  United  States. 

Bermuda  has  a  wind  velocity  much  greater  than 


258  THE  NEW  AIR  WORLD 

that  of  any  of  the  resorts  named  in  the  tables,  and 
its  relative  humidity  is  about  that  of  Florida. 

The  charm  of  Bermuda  is  that  the  flowers  bloom, 
vegetables  grow,  and  the  trees  remain  green  the  year 
round.  Even  though  frequent  short  showers  may 
fall  each  twenty-four  hours  more  than  half  of  the 
days  during  winter,  the  soil  is  so  porous  that  there 
is  little  or  no  mud,  and  life  is  largely  one  of  the  open 
air,  with  a  winter  temperature  that  conduces  to  ac- 
tivity; in  fact,  the  temperature  is  such  that  one 
requires  heavy  clothing  all  the  time  if  one  is  to  sit 
inactive  in  the  open.  There  is  neither  frost,  fog,  nor 
malaria,  nor  snakes. 

Bermuda  lies  666  miles  south  of  New  York  City 
and  about  700  miles  due  east  from  Charleston,  S.  C., 
and  293  miles  from  the  southern  edge  of  the  Gulf 
Stream,  which,  if  the  truth  must  be  told,  exercises 
no  such  influence  on  the  climate  of  Bermuda  as 
highly  colored  advertising  circulars  would  have  one 
believe.  It  is  the  great  ocean,  upon  whose  surface 
the  islands  make  the  most  infinitesimal  dot,  that  con- 
trols the  climate  of  the  Bermudas.  The  Gulf  Stream, 
wonderful  phenomenon  that  it  is,  is  a  sort  of  bug- 
a-boo  to  some  who  never  have  intelligently  studied 
ocean  meteorology.  Travelers  tell  of  the  super- 
heated atmosphere  they  encountered  on  crossing  the 


HEALTH  AND  PLEASURE  259 

Stream,  and  educators  who  should  know  better 
teach  that  the  entire  climate  of  Europe  is  markedly 
influenced  by  it.  The  fact  is  that  there  is  no  dis- 
tortion whatever  of  the  isothermal  lines  as  they 
enter  and  leave  the  Gulf  stream  in  any  region  north 
of  Bermuda.  (See  Chart  14.)  The  climate  of  Ber- 
muda and  of  Europe  is  controlled  largely  by  the 
great  Atlantic  Ocean,  not  by  this  small  river  of  warm 
water,  which  broadens  out  and  loses  its  identity 
long  before  the  coast  of  Europe  is  reached,  and  whose 
influence  is  soon  dissipated  in  the  vast  expanse  of 
ocean  air.  The  ocean  has  a  great  circulating  system, 
northward  on  the  western  and  southward  on  its  east- 
ern side.  This  circulation  pushes  the  isothermal  lines 
northward  on  one  side  and  southward  on  the  other. 
The  islands  of  Bermuda  rise  some  15,000  feet  from 
the  floor  of  the  ocean,  and  project  above  the  water 
to  heights  varying  from  50  to  260  feet  above  sea 
level.  Like  jewels  nestling  upon  the  bosom  of  a 
sub-tropical  ocean  these  islands,  from  one  half  to 
three  miles  wide,  are  strung  along  so  close  that  one 
almost  can  hop  over  from  one  to  the  other.  They 
lie  in  the  form  of  a  fish-hook ;  from  the  hole  where 
the  line  of  the  fisherman  would  be  tied  to  the  point 
of  the  hook  is  about  twenty-six  miles.  The  topog- 
raphy is  irregular  and  picturesque.  On  land  there 


260  THE  NEW  AIR  WORLD 

are  caves  and  grottoes  and  subterranean  lakes.  Jan- 
uary to  May  rose  borders  are  abloom.  In  April  the 
oleander  is  showing  pink  and  crimson  along  every 
roadside,  and  the  hedges  hold  these  beautiful  flowers 
for  months ;  at  Easter  time  lilies  carpet  the  ground 
and  perfume  the  air.  Here  morning  glories  have 
many  forms  and  colors,  which,  with  pendent  bells, 
climb  wide-spreading  cedar  trees,  and  wild  passion 
flowers  cover  rocky  cliffs. 

The  sea  is  so  transparent  that  many  feet  below 
the  surface  the  eye  may  follow  the  movements  of 
marine  life  housed  about  by  coral  formations  of 
strange  devices.  The  colors  of  the  sea  are  as  change- 
able as  the  opal.  Over  shallow  bottoms  the  colors 
are  delicate  shades  of  light  green,  over  the  shoals 
brownish  hues,  and  beyond  the  dangerous  reefs,  which 
have  sent  many  a  sailor  to  his  long  home,  and  behind 
which  numerous  pirates  of  old  have  taken  refuge,  the 
waters  vary  from  the  light  blue  of  the  sapphire  to  deep 
green.  The  prismatic  colors  are  forever  laughing 
and  dancing  to  the  eye  of  the  beholder.  The  shadow 
of  a  cloud,  a  ripple  of  the  surface,  a  different  angle  to 
the  fall  of  sunshine  as  the  day  advances,  deepen  or 
brighten  the  tints  through  a  wide  range  of  color. 

Through  the  glass  bottom  of  a  boat  one  may  look 
into  the  gardens.  Rising  from  the  bottom  and 


HEALTH  AND  PLEASURE  261 

waving  gracefully  with  the  movements  of  the  waters, 
like  tree  ferns  moved  by  gentle  zephyrs,  are  purple 
sea  fans  and  tall  black  rods.  Beautifully  colored 
fishes  dart  about,  or  lazily  bask  in  the  sun  that  il- 
lumines their  coral  grottoes ;  weeds  of  many  colors ; 
green  and  scarlet  sponges ;  vegetable  growths  delicate 
in  formation  and  brilliant  anemones  cling  to  ledges 
of  rock  that  here  and  there  are  tinted  with  pink. 

Rival  champions  of  the  east  and  the  west  coasts 
of  Florida  may  fortify  themselves  by  a  study  of  the 
tables.  It  may  be  noted  that  Miami  and  Tampa 
have  the  same  midday  temperature,  but  that  Tampa 
has  a  greater  range,  the  night  temperature  on  the 
average  falling  five  degrees  lower  than  Miami ;  also 
that  Tampa,  which  can  be  taken  as  typical  of  St. 
Petersburg,  has  but  twenty-one  rainy  days  on  an 
average  from  December  to  March  inclusive,  while 
Miami  has  thirty-four.  Bermuda  has  sixty-five 
days  with  rain  during  the  period,  with  much  wind. 
From  these  data  one  may  select  the  climate  that 
best  suits  him  and  he  may  know  that  the  data  are 
accurate  and  put  forth  by  some  one  not  interested 
in  advancing  the  interest  of  one  place  over  another. 
No  country  in  the  world  has  more  delightful  and 
healthful  climates  for  winter  and  for  summer  than 
can  be  found  in  the  wide  domain  of  the  United  States. 


THE  NEW  AIR  WORLD 


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HEALTH  AND  PLEASURE  265 

The  Scientific  American  thus  speaks  of  the  uses  of 
climatic  data : 

"  What  are  climatic  statistics  good  for  ?  To  this 
query  one  is  tempted  to  retort :  What  are  they  not 
good  for?  Let  us  set  down  a  few  typical  cases  in 
which  such  data  are  desired. 

"  A  merchant  plans  to  undertake  the  sale  of  rub- 
ber coats  in  foreign  markets.  Hence  he  wishes  to 
know  all  about  the  distribution  of  rainfall,  both 
geographically  and  as  to  season.  Which  are  the 
rainy  regions  of  the  globe?  When  do  the  heaviest 
occur  in  each  of  these  regions  ?  Where  do  the  pre- 
vailing temperatures  indicate  the  need  of  heavy 
coats,  and  where  light  ? 

"  An  invalid  contemplates  visiting  a  certain  health 
resort.  What  mean  temperatures  occur  there  at 
the  season  of  the  proposed  visit  ?  What  ranges  of 
temperature  between  day  and  night  ?  How  much 
does  the  temperature  vary  from  day  to  day  ?  How 
much  sunshine  may  be  expected?  Is  the  atmos- 
phere moist  or  dry  ?  What  of  the  winds  ?  Such 
are  some  of  the  questions  he  is  likely  to  ask. 

"A  horticulturist  proposes  to  introduce  a  foreign 
plant  in  this  country.  Where  will  he  find  the  most 
favorable  climate  for  it?  In  order  to  settle  this 
question  he  first  tries  to  secure  certain  information 
about  the  climate  of  the  plant's  original  habitat  — 
the  march  of  temperature  through  the  season  of 
growth,  average  dates  of  first  and  last  frost,  normal 
fluctuations  of  rainfall,  humidity,  sunshine,  etc. 
If  the  desired  information  is  obtained,  the  next 


THE  NEW  AIR  WORLD 

step  is  to  ascertain  where  (if  anywhere)  similar 
climatic  conditions  prevail  in  the  United  States, 
and  this  is  generally  an  easy  task. 

"An  engineer  is  planning  a  sewer  system.  He 
needs  data  of  excessive  rainfall  for  the  locality  under 
consideration,  so  that  he  may  estimate  the  maxi- 
mum amount  of  storm-water  the  sewers  will  ever 
need  to  dispose  of  in  a  given  time.  Their  capacity 
should  not  exceed  this  amount  beyond  a  reason- 
able margin  of  safety :  otherwise  cost  of  construc- 
tion would  be  unnecessarily  great. 

"  This  list  of  examples  might  be  extended  almost 
indefinitely.  It  will  suffice,  however,  to  show  how 
wide  a  range  of  climatic  information  is  required  to 
meet  all  possible  demands.  The  different  branches 
of  industry  are  concerned  with  different  sets  of  cli- 
matic data.  One  set  helps  determine  the  best  lo- 
cation for  a  railroad :  another  the  kind  of  goods 
that  will  be  shipped  over  it  and  the  way  in  which 
they  will  need  to  be  packed  and  cared  for  during 
shipment.  The  climatic  conditions  that  must  be 
considered  in  planning  a  military  campaign  are 
quite  unlike  those  that  engage  the  attention  of  a 
hydrological  engineer  in  laying  out  a  system  of  irri- 
gation. Climatic  statistics  of  interest  to  aviators 
are  not  identical  with  those  that  bear  upon  the  prob- 
lems of  ecology  or  forestry  or  sanitation.  In  short, 
climate  means  different  things  to  different  people." 

Christmas  in  Many  Climes.  A  general  idea  of 
the  diversification  of  climate  may  be  gathered  from 
a  description  of  the  weather  of  some  particular  day 


HEALTH  AND  PLEASURE  267 

of  the  year  as  it  exists  in  many  different  parts  of  the 
world.  One  is  too  prone  to  assume  that  the  weather 
one  has  on  a  given  day  prevails  everywhere.  For 
the  moment  one  does  not  consider  the  effect  of  dis- 
tance from  the  equator,  proximity  to  large  bodies  of 
water,  and  elevation  above  sea  level  and  above  the 
surrounding  region.  When  a  holiday  or  any  day  of 
special  interest  occurs,  while  the  weather  cannot 
make  the  occasion  a  success,  it  can  quite  effectively 
destroy  all  pleasure  in  the  event.  When  we  ap- 
proach the  day  of  all  days  in  the  year  when  two 
fifths  of  the  people  of  the  world  celebrate  the  natal 
day  of  Christ,  interest  in  the  weather  increases. 
The  little  ones  of  our  clime  pray  that  a  mantle  of 
snow  may  cover  the  ground,  so  that  dear  old  Santa 
Claus  may  come  with  his  reindeer  and  sleigh.  The 
boys  and  girls  long  for  the  snow-covered  hillsides 
and  the  glassy  ponds ;  and  even  our  good  old  grand- 
mother smiles  in  anticipation  of  such  a  Christmas 
Day  as  gladdened  her  heart  when  she  was  a  wee  tot. 
It  may  be  interesting  to  know  under  what  kind 
of  skies  the  people  of  other  lands  celebrate  this  in- 
ternational holiday.  In  the  Northern  Hemisphere 
places  near  the  same  latitude  may  have  weather  con- 
ditions greatly  at  variance  the  one  from  the  other, 
because  of  conditions  previously  explained.  It  is 


THE  NEW  AIR  WORLD 

our  winter  now;  not  because  the  sun  is  farthest 
from  us,  for  in  five  days  the  earth  will  reach  the  time 
of  perihelion  in  its  course  around  the  sun,  and  be 
nearer  to  the  central  luminary  than  at  any  other  time 
of  the  year,  but  because  the  inclination  of  the  earth's 
axis  causes  us  to  receive  the  rays  of  the  sun  at  a  lower 
angle  than  during  any  other  season  and  its  intensity 
is  reduced.  The  conditions  are  reversed  to  the 
people  of  the  Southern  Hemisphere;  they  now 
receive  the  most  direct  rays  of  the  sun  and  have 
their  summer,  which  is  intensified  by  the  nearness  of 
the  earth  to  the  sun. 

The  event  that  gave  origin  to  our  Christmas  holi- 
day occurred  nearly  two  thousand  years  ago  in 
Bethlehem  of  Judea;  and  it  may  be  a  new  idea  to 
us  to  try  to  think  of  the  weather  that  prevailed  at 
that  time  and  the  character  of  the  Christmas  Day 
that  land  may  have  this  year.  We  know  that  it 
was  not  cold  and  cloudy  on  that  eventful  night  so 
long  ago,  for  the  shepherds  were  feeding  their  flocks 
upon  the  hillsides  and  the  Wise  Men  of  the  East 
beheld  a  star  and  followed  it.  The  star  shone 
brightly  from  the  time  they  left  Herod  until  they 
reached  the  place  where  the  Infant  lay.  We  may 
therefore  judge  that  this  part  of  their  journey  was 
made  under  a  clear  sky  and  that  the  same  conditions 


HEALTH  AND  PLEASURE  269 

prevailed  at  Bethlehem.  Weather  observations 
made  at  Jerusalem,  a  few  miles  from  Bethlehem, 
during  modern  times,  show  that  during  December 
there  are  less  than  fourteen  cloudy  days  on  the 
average.  The  prevailing  winds  are  from  the  Medi- 
terranean Sea,  only  thirty  miles  to  the  west  of 
Bethlehem,  and  therefore  rarely  does  the  tempera- 
ture exceed  65°  during  the  day  or  fall  to  freezing 
at  night.  While  there  is  evidence  that  the  climate 
is  drier  now  throughout  all  of  the  Holy  Land  than 
at  the  birth  of  Christ,  it  is  highly  probable  that 
when  He  was  born  the  stars  were  shining  brightly 
and  the  hills  were  green  and  beautiful  and  the 
weather  smiling  its  benediction  upon  the  Son  of 
God. 

We  now  will  glance  at  the  weather  that  experience 
teaches  us  will  probably  prevail  in  some  of  the  prin- 
cipal cities  of  the  world  on  Christmas  Day,  and 
thus  have  impressed  upon  us  the  fact  that  on  any 
day  of  the  year  humanity  lives  under  widely  differ- 
ing weather  conditions  throughout  the  world. 

In  our  own  country  we  know  that  Maine  is  the 
home  of  ice,  snow,  and  chilling  blasts,  while  in 
California  and  Florida  orange  blossoms  perfume  the 
temperate  air. 

In  London  Christmas  is  not  always  bright  and 


270  THE  NEW  AIR  WORLD 

comfortable,  for  on  the  average  twenty -one  days  in 
December  are  cloudy  and  the  temperature  ranges 
from  a  few  degrees  below  freezing  at  night  to  about 
50°  during  the  day. 

In  Paris  the  weather  is  about  the  same  as  in 
London.  It  has  the  same  percentage  of  cloudiness, 
and  its  daily  range  of  temperature  is  from  32°  to  45°, 
slightly  colder  than  London.  The  influence  of 
wind  direction  and  the  relation  of  water  and  land 
areas  to  the  location  of  a  city  are  well  exemplified 
in  the  fact  that  Paris,  farther  south  than  London, 
has  a  lower  whiter  temperature.  In  the  United 
States  the  coldest  whiter  winds  are  from  the 
northwest  and  they  also  would  be  so  in  Western 
Europe  were  it  not  for  the  fact  that  they  draw 
from  the  ocean,  whose  waters  are  much  warmer 
in  winter  than  the  interior  of  the  continent  of  Europe. 
The  northeast  winds  are  therefore  the  coldest  that 
come  to  Paris  and  London.  In  the  first  case  they 
draw  from  the  cold  interior,  and  in  the  second  case 
the  air  in  passing  to  London  from  the  northeast 
must  pass  over  the  North  Sea  and  the  extreme 
temperature  of  the  cold  land  is  somewhat  modified 
by  even  this  comparatively  small  body  of  water 
with  the  result  that  the  average  daily  maximum 
temperature  of  London  for  December  is  five  degrees 


HEALTH  AND  PLEASURE  271 

warmer  than  its  neighbor  some  two  hundred  miles 
farther  south. 

Berlin  and  Vienna  have  the  same  degree  of  cloud- 
iness, but  there  the  similarity  ceases.  Berlin,  only 
about  one  hundred  miles  from  the  Baltic  Sea  on  the 
northeast  and  about  double  this  distance  from  the 
North  Sea  on  the  northwest  has  an  average  range 
of  but  eight  degrees  between  day  and  night  tempera- 
tures, while  Vienna,  deep-set  in  the  interior  of  a 
great  continent,  has  a  daily  range  of  thirty-seven 
degrees,  the  average  temperature  swinging  from 
13°  to  50°  each  day  during  December. 

Constantinople  was  named  after  the  Roman 
Emperor  who  made  it  his  capital  and  who  first  pro- 
tected the  early  Christians  from  persecution,  then 
became  converted  and,  in  the  manner  of  his  time, 
forced  others  to  accept  the  doctrine  at  the  point  of 
the  sword.  Here  Christianity  was  first  recognized 
and  adopted  as  a  State  religion,  but  since  the  middle 
of  the  fifteenth  century  Constantinople  has  been 
the  home  of  the  Sultan  of  Turkey  and  the  principal 
city  of  those  who  worship  Muhammid  as  the  prophet 
of  God  instead  of  Christ.  This  ancient  city,  so 
interwoven  in  the  history  of  Christianity,  has  a 
delightful  climate  at  Christmas  time,  the  daily 
range  being  from  between  a  little  above  freezing 


272  THE  NEW  AIR  WORLD 

and  65°  or  70°,  with  clouds  obscuring  the  sky  about 
one  half  the  time. 

Historical  Rome  has  about  as  many  clear  days  as 
cloudy  ones  and  the  days  are  pleasant  and  the  nights 
simply  cool. 

At  Cairo,  hi  the  land  where  Joseph  was  sold  into 
bondage  and  where  Pharaoh  raised  him  to  the 
highest  position  in  the  land  next  to  his  own,  no  more 
delightful  place  can  the  traveler  find  at  Christmas 
time.  Only  one  day  in  three  is  cloudy  and  the 
gentle  winds  are  warm  and  balmy,  with  a  daily 
range  in  temperature  of  12°. 

In  Calcutta  there  is  a  great  amount  of  sunshine, 
only  one  day  in  five  being  cloudy,  with  an  average 
daily  minimum  temperature  of  58°  and  a  maximum 
of  80°. 

Bombay  is  also  sunshiny  at  this  time  of  the  year 
and  excessively  hot,  with  a  range  each  day  from  66° 
to  88°.  Here,  as  at  Calcutta,  Brahmanism  and 
Buddhism  rule  instead  of  Christianity. 

China,  that  enormous  empire  that  believes  in  the 
ethical  philosophy  of  Confucius,  whose  inhabitants 
have  lived  for  four  thousand  years  with  less  strife 
and  bloodshed  than  any  other  nation,  has  as  great 
a  variety  of  climate  during  December  in  the  widely 
separated  parts  of  its  broad  domain  as  has  the  United 


HEALTH  AND  PLEASURE  273 

States.  On  any  day  of  the  Christmas  month  some 
parts  of  this  country  are  bound  in  icy  chains,  while 
other  parts  are  sweltering  in  a  torrid  temperature. 

That  wonderful  Island  —  Japan  —  whose  people 
have  made  such  amazing  strides  in  catching  up  with 
the  most  advanced  civilization  of  the  Occident,  and 
who  never  have  accepted  Christianity,  has  a  most 
delightful  climate  during  winter,  with  a  large  amount 
of  sunshine  and  moderate  temperatures. 

The  vast  Christian  nation  so  long  ruled  by  the 
Tzar,  and  now  in  such  deplorable  chaos,  has  a  varied 
climate  during  December.  From  temperate  con- 
ditions in  the  southern  portion  of  its  European 
possessions  it  gradually  grows  colder  as  one  goes 
northward  until  a  region  of  great  severity  is  reached. 
At  Petrograd  the  average  night  temperature  is  6° 
below  zero.  At  Moscow  it  is  colder,  the  average 
of  its  minimum  temperature  being  11°  below.  Two 
thirds  of  the  time  it  is  cloudy  at  these  two  cities. 

Verkhoyansk,  in  the  central  portion  of  Siberia,  is 
nearly  the  coldest  place  in  the  world  where  observa- 
tions are  regularly  taken.  There  Christmas  Day  may 
be  ushered  in  with  a  temperature  as  low  as  75°  below 
zero.  For  days  at  a  time  this  extreme  cold  remains, 
the  warmest  part  of  the  day  varying  but  little  from 
the  coldest. 


274 


THE  NEW  AIR  WORLD 


In  many  of  the  cities  of  the  Southern  Hemisphere 
Christmas  Day  is  likely  to  be  such  as  will  cause  the 
sojourner  to  long  for  some  cooler  region.  There 
it  is  midsummer,  the  grass  is  green  and  the  fruit  is 
on  the  tree.  We  of  the  North  could  hardly  realize 
that  it  is  December.  In  the  pampas  of  the  Argen- 
tine Republic  everything  is  parched.  The  white 
stucco  walls  and  the  red  tile  roofs  in  the  cities  reflect 
the  intense  rays  of  the  sun  into  the  shimmering  air. 
In  Rio  de  Janeiro  the  days  are  almost  unbearable,  the 
daily  temperature  rising  to  100°  and  over  at  midday 
and  seldom  falling  to  60°  at  night.  Bear  in  mind 
that  the  greater  part  of  the  area  of  South  America 
lies  between  the  equator  and  30°  south  latitude. 
But  wherever  in  these  South  American  cities  one 
can  escape  to  an  elevation  of  several  thousand  feet 
a  pleasant  temperature  may  be  found. 

At  Santiago,  Chili,  it  is  more  comfortable  than  in 
Brazil,  for  the  nights  are  cool,  even  though  the  day 
temperatures  rival  those  of  the  Argentine  Republic. 
But  here  the  cool  mountain  tops  are  almost  hanging 
over  the  coast  cities. 

At  Cape  Town,  in  the  extreme  south  part  of  Africa, 
two  days  out  of  three  are  clear  and  the  daily  range 
of  temperature  is  from  48°  to  83°,  making  fairly 
pleasant  conditions  during  the  Christmas  holidays. 


HEALTH  AND  PLEASURE  275 

At  Melbourne,  Australia,  one  half  of  the  days  are 
cloudy,  and  the  temperature  is  moderate,  having  a 
range  from  54°  to  75°. 

Thus  we  see  that  the  climatological  features  of 
the  world,  not  only  on  Christmas  but  on  any  other 
day  of  the  year,  are  as  varied  as  the  hopes  and 
wishes  of  man,  and  whatever  his  desires  or  physical 
necessities  may  be,  a  climate  may  be  found  under 
the  influence  of  which  he  may  find  pleasure  and 
gain  health. 

The  Hottest  and  the  Coldest  Places  in  the  World. 
It  is  an  innate  characteristic  of  the  human  race  to  be 
interested  in  the  abnormal,  whether  it  be  in  the 
achievements  of  men  or  in  the  extremes  of  natural 
phenomena.  This  is  especially  true  with  regard  to 
the  weather.  During  periods  of  extremes  of  heat 
or  cold  the  natural  inquiry  is  as  to  whether  there 
ever  has  been  a  period  of  equal  or  greater  severity. 
Although  suffering  intensely  there  always  is  a  desire 
to  "  beat  the  record."  It  therefore  may  be  of 
interest  briefly  to  refer  to  the  hottest  and  the  cold- 
est places  in  the  world. 

North  America.  One  of  the  most  torrid  places  in 
the  United  States  is  in  that  remarkable  region  known 
as  Death  Valley.  It  is  located  in  Southern  Cali- 
fornia. Its  name  is  supposed  to  be  derived  from  a 


276  THE  NEW  AIR  WORLD 

melancholy  tragedy  that  occurred  in  1850,  in  which 
every  member  of  a  party  of  emigrants  perished  in 
Death  Valley  from  thirst  and  exhaustion,  leaving 
the  bones  of  themselves  and  their  animals  to  whiten 
in  the  sun.  The  valley  is  the  bed  of  an  ancient  salt 
sea  which  existed  when  the  climate  was  much 
wetter  than  now ;  its  soil  is  largely  composed  of  sand, 
salt,  and  borax.  The  borax  deposits  are  large;  at 
places  they  form  crusts  that  support  the  weight  of 
travelers.  The  length  of  the  valley  is  seventy- 
five  miles,  but  it  is  narrow  at  the  bottom,  in  places 
being  no  more  than  six  miles.  One  of  its  remarkable 
features  is  that  its  bottom,  in  many  places,  is  three 
hundred  feet  below  the  level  of  the  sea,  one  hundred 
miles  to  the  west.  It  is  fed  by  several  small  streams 
and  innumerable  warm  springs,  the  water  from  which 
is  entirely  absorbed  by  the  porous  soil,  although 
water  may  be  found  by  digging  down  a  few  feet. 
The  water  is  unfit  for  use.  It  is  a  desolate  and 
forbidden  region,  inhabited  by  gnats,  toads,  lizards, 
and  snakes.  However,  the  employees  of  a  company 
engaged  in  the  business  of  marketing  borax  spend 
a  portion  of  each  year  there. 

In  1891  an  observer  of  the  U.  S.  Weather  Bureau 
remained  in  Death  Valley  from  May  to  September, 
during  which  time  he  made  daily  observations  of 


HEALTH  AND  PLEASURE  277 

the  weather.  His  experience  was  a  most  trying 
one,  drawing  heavily  upon  his  physical  and  mental 
stamina  to  complete  the  period  of  time  that  had  been 
set  for  him.  For  the  entire  time  of  one  hundred 
and  fifty-four  days  less  than  one  half  an  inch  of 
rain  fell.  There  occurred  several  days  in  succession 
with  a  temperature  of  122°.  However,  this  is  not 
the  highest  temperature  ever  recorded  in  the  United 
States.  In  July,  1887,  at  Mammoth  Tank,  in  the 
Colorado  Desert,  the  temperature  reached  128° 
in  the  shade,  and  again,  in  1884,  124°  was  reached 
at  the  same  place.  On  July  18,  1891,  in  Death 
Valley,  the  maximum  was  120°  and  the  minimum 
99°,  making  an  average  for  all  hours  of  108.6°.  The 
extremely  high  temperatures  reached  in  the  Colorado 
Desert,  which  embraces  a  portion  of  Southern  Cali- 
fornia and  Arizona,  do  not  vary  greatly  from  those 
of  Death  Valley ;  they  are  not  exceeded  anywhere  in 
Central  or  North  America.  Such  degrees  of  heat, 
if  experienced  for  two  or  three  weeks  in  the  more 
humid  regions  of  the  eastern  half  of  the  United 
States,  would  nearly  depopulate  the  region  by  the 
havoc  of  death. 

The  lowest  temperatures  in  the  United  States 
occur  in  extreme  northern  portions  of  Minnesota, 
North  Dakota,  and  Montana,  where  temperatures 


278  THE  NEW  AIR  WORLD 

from  50°  to  55°  below  zero  have  been  recorded.  It 
is  interesting  to  note  that  in  this  same  region  the 
summer  temperatures  have  risen  to  readings  of  from 
105°  to  108°.  Of  course  this  heat  is  quite  different 
in  its  effects  upon  life  from  the  heat  of  the  Gulf  or 
Atlantic  coasts.  One  feels  a  marked  difference  be- 
tween the  sun  and  the  shade  temperatures  in  these 
semi-arid  regions.  Sunstroke  is  infrequent  and  death 
seldom  results  from  exposure,  as  it  does  in  the  East. 

The  region  of  severest  cold  in  North  America  is 
found  about  the  Great  Bear  Lake  in  the  British 
Northwest  Territory,  where  temperatures  of  58° 
below  zero  have  been  recorded. 

South  America.  The  hottest  portion  of  South 
America  is  in  the  interior,  with  extensive  systems 
of  mountain  ranges  along  the  coast  preventing 
the  inward  flow  of  the  moist  rain-bearing  winds 
from  the  ocean.  In  a  stretch  of  country  extending 
from  Uruguay  northward  into  the  interior  of  Brazil, 
the  average  of  the  highest  temperature  of  each 
year  for  a  period  of  several  years  is  104°,  with  indi- 
vidual readings  much  higher.  Except  on  the  top 
of  the  mountains,  or  well  up  their  sides,  no  severely 
cold  weather  occurs  in  South  America,  seven  eighths 
of  its  territory  lying  between  the  equator  and  lati- 
tude 30°  south. 


HEALTH  AND  PLEASURE  279 

Africa.  In  Africa  is  to  be  found  the  hottest 
region  of  the  world,  the  great  Desert  of  Sahara, 
upon  whose  sands  beats  down  the  fierce  tropical 
sun  with  merciless  intensity.  Here  shade  tempera- 
tures of  130°  are  frequently  experienced.  Only 
those  bred  to  extreme  tropical  desert  heat  can  long 
live  under  such  conditions.  In  a  portion  of  the 
desert  lying  between  Egypt  and  the  Red  Sea  the 
temperature  has  been  known  not  to  fall  below  113° 
for  a  period  of  ten  days,  while  on  several  nights  the 
lowest  temperature  reached  was  118°,  with  a  practi- 
cally calm  air.  Africa  lies  with  about  one  half  of  its 
immense  area  on  each  side  of  the  equator,  and  the 
greater  part  of  its  territory  inside  the  Tropical  Zone. 
Except  in  a  few  isolated  cases  on  high  mountains, 
temperatures  as  low  as  zero  never  are  experienced. 

Europe.  The  warmest  portion  of  Europe  is  in  the 
region  round  and  about  the  Mediterranean  Sea. 
The  coldest  places  in  all  Europe  are  in  the  western 
part  of  Russia  and  in  the  northern  part  of  the  Scan- 
dinavian Peninsula.  Here  the  average  of  the  coldest 
days  of  winter  is  50°  below  zero. 

Asia.  It  is  difficult  to  determine  in  what  part  of 
Asia  the  highest  temperature  occurs,  as  data  from 
many  parts  are  meager.  It  is  known  however  that 
extremely  hot  weather  prevails  in  India  and  Arabia. 


280  THE  NEW  AIR  WORLD 

Siberia,  however,  experiences  the  coldest  weather 
to  be  found  anywhere  in  the  world.  At  Wercho- 
jansk,  in  that  country,  a  temperature  of  90.4°  be- 
low zero  was  observed  in  January,  1884,  while  the 
average  temperature  for  the  whole  month  was 
69.4°  below  zero. 

The  coldest  weather  of  the  world  is  not  found 
at  the  North  or  the  South  Pole,  as  many  suppose, 
but  rather  at  the  center  of  vast  continents,  far  from 
the  modifying  influence  of  oceans. 

Australia.  In  extreme  heat  the  interior  of  Aus- 
tralia is  fairly  comparable  with  northern  Africa, 
Persia,  Afghanistan,  and  northern  India,  where 
every  year  maximum  temperatures  of  115°  occur, 
and  where,  at  times,  an  extreme  heat  of  120°  or 
125°  is  experienced  in  the  shade. 

We  now  know  that  the  forceful,  dominating 
peoples  come  out  of  the  regions  where  the  heat  is 
not  so  great  as  to  debilitate,  nor  the  cold  so  fierce 
as  to  deaden  the  mental  and  the  physical  faculties ; 
but  rather  from  the  region  of  the  thoroughfare 
of  the  great  circum-polar  storm  tracks,  where  there 
are  frequent  changes  of  weather  from  sunshine  to 
clouds,  and  where  there  is  a  fairly  wide  difference 
in  temperature  between  night  and  day  and  between 
winter  and  summer.  For  the  best  coordination 


HEALTH  AND  PLEASURE  281 

of  the  mental  and  the  physical  faculties,  so  as  to 
produce  the  most  efficient  composite  of  man,  the 
temperature  should  range  between  45°  and  50°  at 
night  and  between  65°  and  70°  during  the  day,  with 
about  sixty -five  to  seventy  per  cent,  of  relative  hu- 
midity. Some  day  we  will  artificially  create  the 
exact  conditions  of  temperature  and  moisture  needed 
for  patients  in  hospitals  and  sanitaria.  Science  is 
persistently  seeking  means  to  increase  comfort  and 
prolong  life. 


CHAPTER  XV 
CONDENSATION 

HOW   HAZE,   RAIN,    SNOW,    HAIL,    FROST,    CLOUD,    AND   FOG 
ARE  FORMED 

Haze  is  what  might  be  called  diluted  cloud  or  fog ; 
it  differs  from  them  only  in  the  degree  of  its  density. 
One  may  see  several  miles  through  a  haze,  because 
the  minute  particles  of  spheres  of  water  or  ice  are 
far  apart  in  comparison  to  what  they  are  in  fog  or 
cloud. 

Raindrops  vary  in  size  from  0.03  to  0.20  of  an 
inch  in  diameter.  Each  drop  is  composed  of  literally 
millions  of  minute  specks  of  water  that  have  con- 
densed each  about  a  minute  mote  of  dust.  These 
motes  are  a  million  of  times  below  anything  that  may 
be  seen  with  the  most  powerful  microscope.  Recall 
what  is  said  in  Chapter  IV  about  the  size  of  the 
molecules  in  water :  if  a  raindrop  were  enlarged  to 
the  size  of  the  earth,  the  molecules  of  which  it  is 
composed  would  be  no  larger  than  a  baseball,  and 


CONDENSATION  283 

the  smallest  of  them  no  larger  than  tiny  green  peas. 
Without  free  surfaces  upon  which  condensation 
may  begin  there  can  be  no  rainfall.  Dust  motes 
furnish  these  surfaces;  without  them  air  may  be 
supersaturated  without  condensation  occurring  ex- 
cept where  it  comes  in  contact  with  solid  matter. 
The  little  spherical  masses  of  water  join  together  so 
as  to  form  raindrops  in  some  manner  not  well  under- 
stood. When  enough  of  them  coalesce  so  that  the 
weight  of  the  drop  is  too  heavy  to  be  supported  by  the 
motions  of  the  air  it  falls  to  the  ground,  or  is  evapo- 
rated by  the  warmer  and  drier  lower  air.  Rain- 
drops form  mainly  in  the  stratum  between  one  and 
three  miles  above  the  earth.  It  is  seldom  that  the 
stratum  of  air  next  the  earth  is  saturated,  even 
during  rainfall.  One  might  evaporate  millions  of 
gallons  of  water  and  find  no  dust  as  a  residue,  or  at 
least  nothing  visible  to  the  human  eye,  so  infini- 
tesimal are  the  motes  of  condensation.  As  high  as 
thirty  millions  have  been  shown  to  exist  in  a  single 
cubic  centimeter  of  air  (Chapter  IV),  and  a  mil- 
lion times  that  number  could  occupy  such  space 
without  being  visible,  and  the  dust  mote  is  composed 
of  molecules,  and  the  molecules  of  atoms.  It  is 
impossible  for  the  human  mind  to  grasp  the  idea  of 
the  degree  of  smallness  to  which  the  atom  attains, 


284  THE  NEW  AIR  WORLD 

and  when  one  tries  to  conceive  of  the  electrons  from 
which  the  atom  is  built  up,  he  must  try  to  think  of 
them  not  as  objects  but  as  the  place  or  condition 
where  matter  slowly  fades  away  into  nothing;  as 
the  place  possibly  where  matter  is  transmuted  into 
electrical  energy  and  ceases  to  exist. 

The  raindrop  cannot  be  formed  at  great  altitudes 
because  the  vaporous  atmosphere  is  confined  to 
low  levels  by  temperature.  At  100°,  which  often 
exists  at  the  bottom  of  the  atmosphere,  air  at  satura- 
tion contains  19.77  grains  the  cubic  foot;  at  80°, 
10.93;  at  zero,  .04;  and  at  —40°,  which  always 
may  be  found  at  about  four  and  one  half  miles  high, 
air  cannot  contain  in  excess  of  .01  of  a  grain.  Rain- 
drops are  mainly  caused  by  the  cooling  of  air  down 
to  its  dew  point. 

Rain  Water  Is  Not  Pure.  Hailstones  often  incase 
foreign  matter  that  has  been  carried  upward  by  vio- 
lent winds.  Rain  water  is  pure  when  it  is  con- 
densed, but  it  gathers  other  matter  as  it  falls,  such 
as  the  pollen  of  plants,  and  the  broken  siliceous 
shells  of  microscopic  life  carried  by  winds  of  the 
tropics;  it  also  washes  ammonia  from  the  air  in 
small  quantities,  —  about  thirty  pounds  per  acre  in 
the  eastern  half  of  the  United  States  each  year.  A 
raindrop  increases  in  velocity  as  it  falls  until  the  re- 


CONDENSATION  285 

sistance  of  the  air  becomes  just  equal  to  the  weight 
of  the  drop;  after  that  it  falls  at  a  uniform  rate. 
It  will  surprise  many  to  learn  that  if  it  were  not 
for  the  retardation  effected  by  the  resistance  of  the 
air,  a  raindrop  falling  from  only  half  a  mile  would 
be  as  dangerous  to  life  as  a  rifle  bullet,  for  the  speed 
with  which  a  projectile  travels  can  be  made  sufficient 
to  compensate  for  its  softness  or  yielding  qualities. 

How  Much  Water  Is  It  Possible  to  Precipitate 
from  the  Earth's  Atmosphere  ?  If  the  entire  amount 
of  water  vapor  present  in  the  atmosphere  were 
precipitated  instantly  it  would  furnish  a  rainfall 
of  only  two  inches  for  the  whole  surface  of  the 
earth.  A  steady  downpour  for  twenty-four  hours 
usually  amounts  to  some  two  or  three  inches.  Over 
small  areas  and  in  exceptional  cases  as  many  feet 
have  been  known  to  fall  in  that  time,  as  fresh, 
vapor  bearing  winds  steadily  blew  into  a  storm  center, 
rose,  discharged  their  burdens  as  they  cooled  with 
ascent,  and  then  flowed  away,  again  to  be  charged 
with  moisture  when  they  came  into  contact  with 
wet  surfaces.  It  is  impossible  to  drown  the  entire 
earth  with  rainfall,  no  matter  how  long  continued. 

Snow.  Snow  is  water  vapor  condensed  in  the 
congealed  form,  without  passing  through  the  liquid 
state.  When  the  minute  pieces  of  ice  of  which  the 


286  THE  NEW  AIR  WORLD 

flake  is  composed  are  magnified  several  hundred 
times  they  are  found  to  be  composed  of  the  most 
wonderfully  beautiful  figures.  Thousands  have  been 
photographed,  but  the  versatility  of  nature  is  so 
great  that  no  two  ever  have  been  found  that  were 
exactly  alike.  Figure  31  gives  some  idea  of  their 
infinite  variety  and  perfect  symmetry.  They  are 
always  governed  by  the  number  six.  The  most 
common  form  at  the  beginning  of  winter  is  a  six- 
rayed  star,  each  ray  branching.  As  the  winter 
advances  and  the  cold  becomes  more  severe,  the 
flakes  take  a  simpler  form,  finally  becoming  slender 
six-sided  prisms  with  sharp  ends,  under  the  influence 
of  severe  cold  waves.  Great  pain  is  inflicted  on 
the  exposed  parts  of  the  body  when  these  prisms 
are  encountered  in  a  high  wind. 

When  condensation  takes  place  in  a  warm  stratum 
it  will  be  in  the  form  of  minute  massive  spherical 
particles  or  spherules.  If  these  spherules  are  then 
whirled  aloft  by  ascending  currents  it  is  possible 
for  them  to  be  cooled  to  far  below  the  freezing 
point  without  turning  to  ice;  they  will,  however, 
congeal  instantly  when  they  touch  one  another  or 
are  jostled  by  touching  any  solid  or  liquid  surface. 
They  may  give  a  coating  of  ice  to  the  limbs  of  trees 
and  the  coating  may  increase  until  the  limbs  break, 


FIG.  31.  —  SNOW  CRYSTALS. 


CONDENSATION  287 

and  the  surface  of  the  earth  thus  may  be  covered 
with  thin  ice  called  sleet. 

Hail.  There  is  a  difference  of  opinion  among 
meteorologists  as  whether  the  thunderstorm  whirls 
about  a  vertical  axis,  like  the  tornado  and  the 
hurricane,  or  whether  it  rotates  about  a  horizontal 
axis.  One  may  well  account  for  the  formation  of 
the  hailstone  by  assuming  that  its  alternating  layers 
of  snow  and  ice  are  caused  by  the  horizontal  roll 
of  a  thunderstorm,  the  under  part  of  which  has  a 
temperature  at  or  above  freezing  and  the  upper 
half  much  below  freezing.  A  raindrop  is  formed 
hi  the  lower  part,  frozen  in  its  course  through  the 
upper  part,  receives  a  fresh  coating  of  water  or  snow 
with  each  revolution  and  a  freezing  before  its  circuit 
is  completed.  It  thus  gains  in  size  until  it  becomes 
too  heavy  to  be  sustained  by  the  whirling  storm- 
cloud,  when  it  falls  to  earth.  Hail  usually  has  the 
size  of  small  peas,  but  occasionally  it  falls  in  chunks 
sufficiently  large  to  kill  cattle  in  the  fields.  On 
August  15,  1883,  a  hailstone  weighing  eighty  pounds 
is  said  to  have  fallen  in  Kansas. 

Frost.  Frost  is  composed  of  beautiful  crystalli- 
zations, similar  to  snow.  Chapter  VII  describes 
the  process  of  formation  in  detail. 

Cloud.     Cloud  is  formed  by  the  cooling  by  ex- 


288  THE  NEW  AIR  WORLD 

pansion  as  currents  of  air  are  carried  aloft.  Clouds 
are  composed  of  minute  watery  droplets  or  of  ice 
spiculse,  depending  on  their  temperature,  and 
the  latter  largely  is  determined  by  elevation.  A 
cloud  differs  from  mist  or  rain  in  the  size  and  number 
of  its  particles,  and  from  fog  in  its  position  and 
the  method  of  its  formation.  There  are  three 
fundamental  formations,  the  cirrus,  cumulus,  and 
stratus.  The  others  are  combinations  of  these. 
The  cirrus  are  thin,  high,  veil-like  clouds,  always 
composed  of  ice  spiculse;  the  cumulus  look  like 
great  banks  of  snow  with  bulging,  oval  tops  in  which 
thunder  heads  may  form;  the  stratus  spread  out 
like  a  great  blanket.  The  cirrus  usually  fly  at  the 
top  of  the  storm  stratum,  some  five  to  seven  miles 
high ;  the  other  clouds  at  some  lower  level.  When 
ram  is  falling  from  a  cloud,  it  is  called  nimbus. 

Fog  Is  Cloud  at  a  Low  Level.  It  is  formed  by 
warm  water  vapor  rising  from  lakes  or  rivers  into 
the  cool  night  air  at  the  bottom  of  valleys,  or  by  the 
cold  waters  of  oceans  being  forced  up  over  a  bar, 
where  the  coldness  that  they  impart  to  the  adjacent 
air  condenses  some  of  its  vapor. 

Artificial  Rain  Making.  Many  swindlers  have 
preyed  upon  the  credulity  of  the  public  by  claiming 
to  have  a  process  for  the  making  of  rain,  and  in  some 


CONDENSATION  289 

cases  large  sums  of  money  have  been  paid  by  com- 
mercial or  other  associations  to  these  charlatans. 
In  1892  the  United  States  Congress  appropriated 
$20,000  for  the  testing  of  the  theory  that  rain 
could  be  created  by  the  setting  off  of  large  quanti- 
ties of  explosives.  The  experiment  was  unsuc- 
cessful, as  the  scientists  of  the  Government  insisted 
it  would  be.  The  Greeks  had  a  popular  belief  that 
when  a  host  of  their  soldiers  went  out  to  meet  an 
army  of  Persians  the  vapor  rising  from  the  hot 
breath,  blood,  and  sweat  of  the  struggling  mass  was 
later  condensed  into  rain  by  the  concussion  of  the 
battle  clubs  and  the  hoarse  cries  of  the  victors, 
and  many  of  the  veterans  of  our  Civil  War  were 
firm  in  the  opinion  that  their  great  battles  were 
followed  by  rains  that  were  the  result  of  the  can- 
nonading. Both  the  Greeks  and  our  American 
soldiers  were  mistaken.  Rain  often  has  fallen  at  the 
close  of  great  battles,  not  because  of  the  concussion 
of  the  conflict,  but  because  rain  falls  on  an  average  of 
one  day  in  three  in  the  regions  where  most  of  the  great 
battles  have  been  fought,  and  the  movement  of  armies 
began  on  the  fair  days  when  travel  was  good.  If  it 
were  the  custom  to  begin  battles  on  rainy  days 
we  would  have  the  contrary  and  equally  erroneous 
theory  that  concussion  clears  the  atmosphere. 


290  THE  NEW  AIR  WORLD 

Prevention  of  Hail  by  the  Firing  of  Guns.  Even 
a  Papal  decree  was  not  entirely  effective  in  pre- 
venting the  people  in  southern  Europe  from  ringing 
the  church  bells  to  prevent  the  formation  of  hail 
when  a  storm  threatened,  and  within  the  past 
quarter-century  large  grants  of  public  money  were 
foolishly  wasted  in  the  firing  by  the  vineyardists 
of  France  and  other  parts  of  Europe  of  a  gun  spe- 
cially designed  to  destroy  hail  clouds.  These  guns 
sent  harmless  smoke  rings  a  few  feet  aloft.  The 
writer  felt  constrained  to  employ  the  extensive 
machinery  of  the  Weather  Bureau  to  counteract 
the  effect  of  glowing  accounts  of  the  success  of  these 
guns  that  were  sent  to  this  country  by  some  of  the 
ignorant  persons  employed  by  this  Government 
to  represent  us  as  consuls  abroad.  Even  though 
the  hail-destroying  guns  occasionally  were  choked 
with  hail  it  was  difficult  for  scientists  to  prevail 
upon  the  public  to  stop  their  foolish  and  wasteful 
practice. 


CHAPTER  XVI 

DEVELOPMENT  OF  THE  AMERICAN 
WEATHER  SERVICE 

THE      LARGEST     AND     THE     MOST     EFFECTIVE     METEORO- 
LOGICAL BUREAU   IN   THE   WORLD 

EVEN  to  those  who  are  familiar  with  the  appli- 
cation of  meteorological  science  to  the  making  of 
weather  forecasts,  and  with  the  material  benefits 
accruing  to  the  commerce  and  industry  of  the 
United  States  from  timely  warnings  of  marine  storms, 
frosts,  and  cold  waves,  it  will  be  interesting  to  note 
that  at  the  time  of  the  founding  of  the  first  of  the 
thirteen  original  Colonies,  at  Jamestown,  Virginia, 
in  1607,  practically  nothing  was  known  of  the 
properties  of  the  air  or  of  methods  for  measuring 
its  forces.  To-day  electrically  recording  automatic 
meteorological  instruments  measure  and  transcribe 
for  each  moment  of  time  at  two  hundred  stations 
in  the  United  States,  the  temperature,  the  air  pres- 
sure, the  velocity  of  the  wind,  the  direction  of  the 


THE  NEW  AIR  WORLD 

wind,  the  beginning  and  ending  of  rainfall,  with 
the  amount  of  precipitation;  and  the  presence  of 
sunshine  or  cloud;  and  three  thousand  voluntary 
observers  each  day  record  the  temperature  and 
the  rainfall. 

That  we  live  in  an  age  of  great  intellectual  acumen, 
and  that  he  is  indeed  a  wise  prophet  who  can  even 
dimly  outline  the  possibilities  of  the  next  century, 
is  fitly  shown  by  the  development  of  meteorologi- 
cal science  during  the  recollection  of  the  present 
generation ;  although  one  must  admit  that  in  the 
making  of  weather  forecasts,  valuable  as  they  are, 
we  have  not  advanced  beyond  the  partly  empirical 
stage.  It  is,  therefore,  improbable  that  in  the 
making  of  these  forecasts  we  shall  ever  attain  the 
accuracy  acquired  by  theoretical  astronomy  in 
predicting  the  date  of  an  eclipse  or  the  culmination 
of  any  celestial  event. 

It  was  not  until  1644,  twenty -four  years  after  the 
landing  of  the  Pilgrims  at  Plymouth  Rock,  that 
Torricelli  discovered  the  principle  of  the  barometer 
and  rendered  it  possible  to  measure  the  weight 
of  the  superincumbent  air  at  any  spot  where  the 
wonderful  yet  simple  little  instrument  might  be 
placed.  Torricelli's  great  teacher  —  Galileo  —  died 
without  knowing  why  nature,  under  certain  con- 


AMERICAN  WEATHER  SERVICE     293 

ditions,  abhors  a  vacuum,  but  he  had  already  dis- 
covered the  principle  of  the  thermometer.  The  data 
from  the  readings  of  these  two  instruments  form 
the  base  of  all  meteorological  science.  Their  in- 
ventors as  little  appreciated  the  value  of  their  dis- 
coveries as  they  dreamed  of  the  coming  great  west- 
ern empire  which  should  first  use  their  instruments 
to  measure  the  inception  and  development  of  storms, 
and  later,  with  the  aid  of  the  electro-magnetic 
telegraph,  to  give  warnings  to  threatened  regions 
of  the  approach  of  hurricanes,  cold  waves,  floods, 
and  frosts  that  have  been  worth  at  least  one  hun- 
dred million  dollars  to  this  country  during  the  past 
ten  years  without  counting  the  many  thousands 
of  lives  saved  among  mariners. 

Doctor  John  Lining,  of  Charleston,  South  Caro- 
lina, kept  a  daily  record  of  the  temperature  in  this 
country  as  early  as  1738,  although  the  accurate 
thermometers  of  Fahrenheit  had  then  been  hi  use 
but  a  few  years  and  the  errors  due  to  imperfect 
mechanical  construction  may  have  been  consider- 
able as  compared  with  the  refined  instruments 
now  used  for  measuring  temperature.  About  one 
hundred  years  after  the  invention  of  the  barometer, 
viz.,  in  1747,  Benjamin  Franklin,  the  patriot 
and  statesman,  the  diplomat,  the  scientist,  divined 


294  THE  NEW  AIR  WORLD 

that  certain  storms  may  move  in  a  direction  op- 
posite to  the  blowing  of  the  wind  and  that  they  pro- 
gress in  an  easterly  direction.  It  was  prophetic 
that  this  idea  should  come  to  him  long  before 
any  one  had  ever  seen  charts  showing  observations 
simultaneously  taken  at  many  stations.  But  al- 
though his  ideas  in  this  respect  were  more  momen- 
tous than  his  act  of  drawing  the  lightning  from  the 
clouds  and  identifying  it  with  the  electricity  of  the 
laboratory,  yet  his  contemporaries  thought  little 
of  his  philosophy  of  storms,  and  it  was  soon  for- 
gotten. It  will  be  interesting  to  learn  how  he 
reached  his  conclusion  as  to  the  cyclonic  or  eddy- 
like  nature  of  storms.  He  had  arranged  with  a 
co-worker  at  Boston  to  take  observations  of  an 
eclipse  at  the  same  time  that  Franklin  was  taking 
readings  at  Philadelphia.  Early  on  the  evening 
of  the  eclipse  an  unusually  severe  northeast  wind 
and  rainstorm  set  in  at  Philadelphia  and  Franklin 
was  unable  to  secure  any  observations.  He  reasoned 
that  as  the  wind  blew  fiercely  from  the  northeast 
the  storm,  of  course,  was  coming  from  that  direction, 
and  Boston  must  have  experienced  its  ravages  be- 
fore Philadelphia  was  reached.  Reports  indicated 
that  the  storm  was  widespread.  What  was  the 
surprise  of  Franklin,  when,  after  the  slow  passage  of 


AMERICAN  WEATHER  SERVICE     295 

the  mail  by  coach,  he  heard  from  his  friend  in 
Boston  that  the  night  of  the  eclipse  had  been  clear 
and  favorable  for  observations,  but  that  a  terrific 
northeast  wind  and  rainstorm  began  early  the 
following  morning.  Franklin  then  sent  out  inquiries 
to  surrounding  stage  stations  and  found  that 
at  all  places  southwest  of  Philadelphia  the  storm 
began  earlier  and  that  the  greater  the  distance 
the  earlier  the  beginning  as  compared  with  its 
advent  in  Philadelphia;  but  northeast  of  Phila- 
delphia the  time  of  the  beginning  of  the  storm  was 
later  than  at  the  latter  city,  the  storm  not  reaching 
Boston  until  twelve  hours  after  it  began  at  Phila- 
delphia. In  considering  these  facts  a  line  of  inductive 
reasoning  brought  him  to  the  conclusion  that  the  wind 
always  blows  towards  the  center  of  the  storm ; 
that  the  northeast  storm  which  Boston  and  Phila- 
delphia had  experienced  was  caused  by  the  suction 
exercised  by  an  advancing  storm  eddy  from  the 
west  which  drew  the  air  rapidly  from  Boston  toward 
Philadelphia,  while  the  source  of  the  attraction  —  the 
center  of  the  storm  eddy  —  was  yet  a  thousand 
miles  to  the  southwest  of  the  latter  place;  that 
the  velocity  of  the  northeast  wind  increased  as  the 
center  of  the  storm  eddy  advanced  nearer  and 
nearer  from  the  southwest  until  the  wind  reached 


296  THE  NEW  AIR  WORLD 

the  conditions  of  a  hurricane;  that  the  wind  be- 
tween Boston  and  Philadelphia  shifted  its  direction 
so  as  to  come  from  the  southwest  after  the  center  of 
the  storm  eddy  had  passed  over  this  region;  and 
that  the  force  of  the  wind  gradually  decreased  as 
the  center  of  attraction  —  which  always  is  the  storm 
center  —  passed  farther  and  farther  away  to  the 
northeast. 

Another  man  whose  name  is  dear  to  the  heart  of 
every  patriotic  American  conducted,  in  conjunction 
with  a  friend,  a  series  of  weather  observations,  be- 
ginning in  1771  and  continued  during  the  stirring 
times  of  the  Revolution.  This  was  the  sage  of 
Monticello,  Thomas  Jefferson. 

During  the  first  half  of  the  nineteenth  century, 
nearly  a  hundred  years  after  Franklin's  northeast 
rainstorm,  Redfield,  Espy,  Loomis,  Henry,  and 
other  American  scientists  laboriously  gathered  by 
mail  the  data  of  storms  after  their  passage  and 
demonstrated  their  principal  motions  to  be  such 
as  Franklin  had  supposed.  Professor  Joseph  Henry, 
Secretary  of  the  Smithsonian  Institution,  in  1855, 
constructed  the  first  daily  weather  map  from  simul- 
taneous observations  collected  by  telegraph.  He 
did  not  publish  his  forecast  but  used  his  large  wall 
map  for  the  purpose  of  demonstrating  the  feasibility 


AMERICAN  WEATHER  SERVICE     297 

of  organizing  a  Government  weather  service.  If 
there  were  no  other  achievements  to  the  credit  of 
the  institution  founded  in  this  country  through  the 
benevolence  of  the  English  philanthropist,  James 
Smithson,  who,  by  the  way,  never  gazed  upon  our 
fair  land,  the  work  of  the  Smithsonian  Institution 
in  connection  with  practical  meteorology  would 
always  give  it  a  warm  place  in  the  hearts  of  those 
who  believe  the  crowning  achievements  of  science 
consist  in  giving  to  the  world  knowledge  which 
results  in  the  saving  of  human  life,  the  amelioration 
of  the  sufferings  of  human  beings,  and  the  acceler- 
ation of  the  wheels  of  commerce  and  industry. 

Although  American  scientists  were  the  pioneers 
in  discovering  the  progressive  character  of  storms 
and  in  demonstrating  the  practicability  of  weather 
services,  the  United  States  was  the  fourth  Govern- 
ment to  give  legal  autonomy  to  a  weather  service. 
Holland  established  a  weather  service,  with  tele- 
graph reports  and  forecasts,  in  1860;  England 
followed  with  a  smaller  service  in  1861 ;  and  France 
in  1863.  But  none  of  these  countries  has  an  area 
from  which  observations  can  be  collected  great 
enough  to  give  such  a  synoptic  picture  of  storms  as 
is  necessary  in  the  making  of  forecasts  of  much  utility. 
It  would  require  an  international  service,  embracing 


298  THE  NEW  AIR  WORLD 

all  the  countries  of  Europe,  to  equal,  in  extent  of  the 
area  covered  and  of  the  accuracy  of  its  forecasts,  the 
service  of  the  United  States,  which  was  begun  in 
1870,  as  the  result  of  agitation  by  Lapham,  Henry, 
Abbe,  Maury,  and  others. 

The  vast  region  now  brought  under  the  dominion 
of  twice-daily  synchronous  observations  embraces 
an  area  extending  two  thousand  miles  north  and 
south,  three  thousand  miles  east  and  west,  and  so 
fortunately  located  in  the  interest  of  the  meteorolo- 
gist as  to  include  an  important  arc  on  the  circum- 
polar  thoroughfare  of  storms  of  the  northern  hemi- 
sphere. Simultaneous  observations,  collected  twice 
daily  by  telegraph  from  two  hundred  stations, 
distributed  throughout  this  great  area,  renders  it 
possible  at  several  central  offices,  where  all  the 
reports  are  received,  to  present  to  the  trained  eye 
of  the  forecaster  a  wonderful  panoramic  picture 
of  atmospheric  conditions.  Each  twelve  hours  the 
kaleidoscope  changes  and  a  new  graphic  picture  of 
actual  changes  is  shown.  The  movements  of  storm 
centers  and  cold-wave  areas  are  noted  and  estimates 
made  as  to  their  probable  course  during  the  next 
twenty-four  hours.  Where  else  can  the  meteorologist 
find  such  an  opportunity  to  study  storms  and 
atmospheric  changes? 


AMERICAN  WEATHER  SERVICE     299 

In  1870,  and  for  ten  years  thereafter,  our  fore- 
casts and  storm  warnings  were  looked  upon  by  the 
press  and  the  people  more  as  experiments  than  as 
serious  statements.  The  newspapers  especially  were 
prone  to  facetiously  comment  on  the  forecasts,  and 
many  were  clamorous  for  the  abolition  of  the  service 
during  the  first  years  of  its  existence.  There  was 
some  ground  for  the  criticisms.  We  knew  nearly 
as  much  about  the  mechanics  of  storms  at  that  time 
as  we  do  to-day,  but  we  had  not,  by  a  daily  watch- 
ing of  the  inception,  the  development,  and  the 
progression  of  storms,  trained  a  corps  of  expert 
forecasters,  such  as  now  form  a  part  of  the  staff  of 
the  Chief  of  the  Weather  Bureau,  and  from  which 
the  writer  was  graduated  before  he  became  Chief. 
Along  about  1880,  mariners  began  to  note  that 
danger  signals  were,  in  far  more  than  a  majority  of 
cases,  followed  by  heavy  winds ;  they  began  to 
reason  that  it  would  be  better  to  take  precaution 
against  storms  that  never  came,  than  to  be  unpre- 
pared for  those  which  did  come  according  to  the 
forecasts. 

It  is  a  fact  that  many  times,  by  the  operation  of 
forces  not  indicated  by  the  surface  readings,  the 
barometer  at  the  center  of  a  storm  begins  to  rise  and 
the  velocity  of  the  whirling  mass  to  decrease.  In 


300  THE  NEW  AIR  WORLD 

such  a  case  the  storm  signals  placed  in  advance  of 
the  storm  center  would  fail  to  give  the  proper  in- 
formation. Again,  the  storm  center  may  suddenly 
acquire  a  force  not  anticipated,  or  it  may  pursue  a 
track  considerably  divergent  from  the  normal  for 
the  location  and  season.  In  this  case,  also,  the 
forecasts  may  warn  some  cities  that  fail  to  receive 
the  effects  of  the  storm.  However,  during  the 
past  few  years  the  staff  of  the  Weather  Bureau, 
which  includes  the  ablest  meteorologists  in  the 
United  States,  has  made  a  study  of  the  peculiarities 
of  the  different  types  of  storms  occurring  in  the 
different  localities  during  the  various  seasons  of 
the  year,  their  line  of  travel  and  the  force  they  may 
be  expected  to  attain.  Competitive  examinations 
have  been  held  to  test  the  comparative  merits  of 
those  who,  by  natural  ability,  are  best  fitted  to 
correctly  and  quickly  correlate  in  their  minds  the 
conditions  shown  on  a  meteorological  chart,  and  to 
make  accurate  deductions  thereform  as  to  the  de- 
velopment, movement,  and  force  of  storms.  This 
line  of  work  and  investigation  has  resulted  in  im- 
proved forecasts;  so  much  so  that  mariners  now 
universally  heed  the  storm  warnings ;  horticulturists 
and  truck  gardeners  make  ample  provision  for 
protection  against  frost;  the  shippers  of  perish- 


AMERICAN  WEATHER  SERVICE     301 

able  produce  give  full  credence  to  the  cold  wave 
predictions.  Of  the  many  West  Indian  hurricanes 
which  have  swept  our  Atlantic  seaboard  from  Florida 
to  Maine  during  the  past  many  years,  not  one  has 
reached  a  single  seaport  without  danger  warnings 
being  sent  well  in  advance  of  the  storm ;  and  few  un- 
necessary warnings  have  been  issued.  The  result 
is  that  few  disasters  of  consequence  have  occurred. 
Large  owners  of  marine  property  estimate  that  one 
of  these  severe  storms  traversing  our  Atlantic 
coast  in  the  absence  of  danger  signals  would  leave 
not  less  than  three  million  dollars'  worth  of  wreckage. 
Twice  a  census  was  taken  just  after  the  passage  of 
severe  hurricanes  to  determine  the  value  of  property 
held  in  port  by  the  danger  warning  sent  out  in  ad- 
vance of  the  storms.  In  one  case  the  figure  was 
placed  at  thirty-four  million  dollars  and  in  the 
other  thirty-eight  million  dollars.  Of  course  this 
does  not  represent  the  value  of  property  saved. 
It  simply  shows  the  value  of  property  placed  in 
positions  of  safety  as  a  result  of  the  danger  signals 
and  warning  messages  sent  to  masters. 

On  January  1,  1898,  an  extensive  cold  wave  swept 
from  the  Rocky  Mountains  eastward  to  the  sea- 
board. Estimates  secured  from  shippers  in  a  hun- 
dred principal  cities  indicate  that  property  valued 


302 


THE  NEW  AIR  WORLD 


at  three  million  four  hundred  thousand  dollars  was 
saved  as  a  direct  result  of  the  predictions  sent  out  well 
in  advance  of  the  coming  of  the  severe  cold.  The 
utility  of  these  forecasts  to  the  agriculture,  the  com- 
merce, and  the  industry  of  the  country  is  so  great  that 
there  is  hardly  a  daily  paper  that  does  not  publish 
weather  forecasts  in  a  prominent  place,  and  there  is 
scarcely  a  reader  who  fails  to  note  the  predictions. 
Twenty-five  years  ago  mariners  on  our  Great 
Lakes  and  seaboard  depended  on  their  own  weather 
lore  to  warn  them  of  coming  storms.  Then,  al- 
though the  number  of  craft  plying  our  waters  was 
much  less  than  now,  every  severe  storm  that 
swept  the  Lakes  or  Atlantic  coast  left  destruction 
and  death  in  its  wake,  and  for  days  afterward  the 
dead  were  cast  up  by  the  receding  waves,  and  the 
shores  were  lined  with  wreckage.  Happily  this  is 
not  now  the  case,  for  the  Weather  Bureau  is  ever 
watching  the  changes  of  atmospheric  conditions,  and 
giving  to  the  mariner  warning  of  coming  storms. 
Each  observer  telegraphs  instantly  to  the  Central 
Office  whenever  the  delicately  adjusted  instruments 
at  his  station  show  unusual  agitation.  By  this 
means  the  inception  of  many  storms  is  detected 
when  the  regular  morning  and  evening  reports  fail 
to  give  notice  of  their  origin, 


AMERICAN  WEATHER  SERVICE     303 

Some  idea  of  the  vast  interests  floating  on  the 
Atlantic  coast  may  be  had  when  it  is  stated  that 
5628  trans-Atlantic  steamers,  with  an  aggregate 
of  10,076,148  tons,  and  5842  sailing  craft,  ag- 
gregating 2,105,688  tons,  entered  and  left  ports  on 
the  Atlantic  seaboard  during  a  single  year  ten  years 
ago,  and  the  record  is  vastly  greater  now.  The 
value  of  their  cargoes  is  more  than  a  billion  and  a 
half  of  dollars.  Our  coastwise  traffic  is  enormous. 
Fifteen  years  ago  more  than  seventeen  thousand 
sailing  vessels  and  four  thousand  steamers  entered 
and  left  the  ports  between  Maine  and  Florida.  The 
number  has  largely  increased  since.  From  these 
facts  one  can  roughly  measure  the  value  of  the  marine 
property  which  the  Weather  Bureau  aims  to  protect 
by  giving  warning  of  approaching  storms. 

It  is  the  expectation  of  the  meteorologist  that 
some  day  he  will  be  able  to  accurately  forecast  the 
weather  for  weeks  and  months  in  advance.  What 
a  wonderful  conservation  of  human  energy  would 
result  if  it  were  possible  to  tell  the  farmer  when  the 
great  corn  and  wheat  belts  would  have  abundant 
ram  during  the  next  growing  season,  or  when 
droughts  would  parch  and  wither  the  vegetation; 
or  to  truthfully  inform  the  planter  of  the  South 
that  the  coming  season  would  be  favorable  or  un- 


304  THE  NEW  AIR  WORLD 

favorable  for  the  production  of  cotton !  Effort 
could  be  withheld  in  one  part  of  the  country,  and 
greater  energy  exerted  in  another. 

This  extension  of  forecasting  doubtless  will  be 
accomplished  as  the  result  of  further  study  of  solar 
impulses  which  disturb  the  orderly  processes  of  the 
earth's  atmosphere  and  initiate  storms,  combined 
with  a  comparative  study  of  meteorological  data. 
We  may  be  laying  the  foundation  of  a  great  edifice 
which  shall  adorn  the  civilization  of  future  centuries. 

As  storms  of  more  or  less  intensity  pass  over  large 
portions  of  our  country  every  few  days  during  the 
greater  part  of  the  year,  and  as  it  is  seldom  that  the 
weather  report  does  not  show  one  or  more  storms  as 
operating  somewhere  within  our  broad  domain, 
it  is  easy  for  some  charlatan  to  forecast  thunder- 
storms about  a  certain  time  in  July,  or  a  cold  wave 
and  snow  about  a  certain  period  in  January,  and 
stand  a  fair  chance  to  accidentally  become  famous 
as  a  prophet.  One  may  select  any  three  equidis- 
tant dates  in  January  and  forecast  high  wind,  snow, 
and  cold  for  New  York  City,  and  stand  a  fair  chance 
of  having  the  fraudulent  forecast  verified  in  two 
out  of  the  three  cases,  provided  that  you  claim  a 
storm  coming  the  day  before  or  the  day  after  one 
of  your  dates  is  the  storm  that  you  expected. 


AMERICAN  WEATHER  SERVICE     305 

From  the  introduction  of  the  electro-magnetic 
telegraph  in  1844  down  to  1869  intermittent  ad- 
vocations  were  made  by  many  in  this  country  for 
a  national  weather  service.  Finally  Doctor  Increase 
A.  Lapham,  of  Milwaukee,  scientist  and  philanthro- 
pist, so  aroused  the  property  and  financial  interests 
of  the  country  with  the  facts  that  he  presented 
relative  to  the  destruction  of  life  and  property  by 
storms  on  Lake  Michigan  that  Congress,  under 
provisions  of  a  bill  introduced  by  General  Halbert 
E.  Paine,  was  induced  to  appropriate  money  to 
initiate  a  service.  To  General  Albert  J.  Meyer, 
Chief  Signal  Officer,  U.  S.  A.,  was  intrusted  the  duty 
of  inaugurating  a  tentative  weather  service  by 
deploying  over  the  country  as  observers  the  mili- 
tary signalmen  of  his  command.  From  this  begin- 
ning has  evolved  the  present  extensive  Weather 
Bureau,  which  is  the  largest  in  the  world  and  more 
intimately  serves  the  needs  of  the  public  than  any 
other. 

In  1869  Professor  Cleveland  Abbe  published  a 
weather  bulletin  at  Cincinnati,  based  upon  simul- 
taneous observations  secured  by  telegraph  from 
about  thirty  stations.  He  was  the  first  scientific 
assistant  to  General  Meyer  and  remained  con- 
tinuously with  the  service  until  his  death  in  1919. 


306  THE  NEW  AIR  WORLD 

Colonel  (afterward  Brigadier-General)  H.  H.  C. 
Dun  woody,  U.  S.  A.,  served  twenty-seven  years  as 
an  expert  forecaster  or  as  the  assistant  chief  of  the 
Weather  Bureau.  General  A.  W.  Greely,  of  Arctic 
fame,  the  last  of  the  military  chiefs,  succeeded 
Brigadier-General  William  B.  Hazen  on  the  death 
of  the  latter.  Professor  Mark  W.  Harrington  was 
the  first  chief  of  the  new  civil  Weather  Bureau;  he 
served  but  four  years  and  was  succeeded  by  Pro- 
fessor Willis  L.  Moore,  who  remained  chief  for 
eighteen  years,  serving  two  years  under  President 
Cleveland,  who  appointed  him,  and  during  the  entire 
administrations  of  McKinley,  Roosevelt,  and  Taft, 
and  was  removed  by  Woodrow  Wilson  immediately 
on  taking  office.  Professor  Moore  claims  the  honor 
of  having  been  the  first  presidential  appointee  to 
incur  the  displeasure  and  receive  the  public  condem- 
nation of  Woodrow  Wilson.  The  present  chief  is 
Professor  Charles  F.  Marvin,  who  for  many  years 
served  as  an  assistant  to  Professor  Moore. 


INDEX 


INDEX 

ABBE,  CLEVELAND,  298 ;  publishes  weather  bulletin,  305 ;  his  long  serv- 
ice in  the  Weather  Bureau,  305 

Absolute  humidity,  39 

Absolute  zero,  62 

Aerial  ocean,  the  air  a  great,  7 

Aeroplane,  importance  of  developing  the,  27 

Africa,  and  monsoon  winds,  107 ;  hottest  and  coldest  places  in,  279 

Agricultural  interests,  benefit  of  Weather  Bureau  service  to,  301,  302 

Air,  great  ocean  of,  around  the  earth,  7 ;  condition  of,  at  various  levels, 
7-17 ;  liquid,  9 ;  blue  tint  of,  10 ;  thinness  of  stratum  of,  that  sus- 
tains life,  14 ;  elasticity  and  density  of,  14 ;  pressure  of,  15 ;  weight 
of,  15;  everything  evolved  from,  15-17;  effect  of  cold  wave  on 
the,  36,  37 ;  explorations  of  the,  18-28 ;  circulation  of  the,  55 ; 
increasing  pressure  increases  temperature  of,  61 ;  difference  be- 
tween weight  and  pressure  of,  77;  course  of  a  current  of,  S9; 
earth  warmer  than,  next  above,  180;  cools  with  ascent  and 
heats  with  descent,  184;  height  of  freezing  cold  in  free,  185; 
daily  range  of  temperature  in  free,  185,  186 ;  movement  of,  in  val- 
leys, 204 ;  mountains  and  movement  of,  205 ;  proper  temperature 
and  humidity  of,  in  habitations,  217 ;  water  vapor  in,  at  various  tem- 
peratures, 284 ;  retards  falling  raindrops,  285 ;  and  the  formation  of 
cloud,  287,  288 

Air  travel,  Major  Blair  on,  27 ;  Lieut.  Col.  Henry  on,  28 

Aitken,  Robert  Grant,  method  of  counting  dust  motes,  44,  45 

Altitude,  gauged  by  boiling  point  of  water,  60,  61 ;  wind's  velocity  in- 
creases with,  109-111 ;  man's  adjustment  to  life  at  high,  186,  187; 
temperature  at  high,  210-212 ;  amelioration  of  disease  by  moderate, 
248,  249,  250 

Altitudes,  the  cold  and  stillness  in  the  higher,  10,  11 

American  Weather  Service,  development  of,  291-306.  See  also  UNITED 
STATES  WEATHER  BUREAU 

Ammonia,  33 

Aneroid  barometer,  volunteer  observers  and  the,  66 ;  forecasting  weather 
with  the,  74-79 

Animal  life,  necessity  of  oxygen  to,  35 


310  INDEX 

Anti-cyclone,  general  cause  of,  98;  general  whirl  of,  103;  gyration  of, 
108,  109;  an  area  of  high  pressure,  119 

Appalachian  Mountains,  effects  of  higher  elevation  of,  231,  232 

Argentine  Republic,  Christmas  Day  in,  274 

Argon,  33 

Arrows,  on  weather  map  fly  with  wind,  116,  118 

Artificial  rain  making,  experiments  with,  288,  289 

Asia,  and  monsoon  winds,  106 ;  hottest  and  coldest  places  in,  279-280 

Astoria,  Wash.,  climate  of,  210 

Atlantic  Ocean,  temperatures  of  waters  of,  177 

Atmosphere,  of  the  sun,  2 ;  of  Jupiter,  Neptune,  Uranus,  and  Saturn,  3 ; 
carbon  dioxide  in,  5 ;  thickness  of  earth's,  6 ;  how  it  is  warmed,  8 ; 
absorption  of  heat  rays  by,  8 ;  water  vapor  in  earth's,  8 ;  tempera- 
ture of  isothermal  stratum  of,  11;  gases  of,  in  mechanical  not 
chemical  union,  32 ;  importance  of  proper  proportions  of  gases  of  the, 
32 ;  table  of  component  parts  of,  33 ;  beneficial  effects  of  cold  wave 
on,  36,  37 ;  dust  motes  and  illumination  of  the,  45 ;  data  meager  as 
to  circulation  of  upper,  103,  104 ;  storms  and  cold  waves  great  ed- 
dies in  the,  118;  variations  in  temperature  due  to  motion  of,  163, 
164 ;  absorption  of  solar  rays  by  the,  166-168 

Atmospheres,  how  they  are  formed,  1 ;  how  maintained  and  how  lost, 
5 ;  earth's  four,  29-47 

Atmospheric  air,  composition  of,  29-37 

Atoms,  early  belief  in  formation  of  all  matter  of,  30 ;  present  knowledge 
of,  30,  31 ;  composition  of,  31 ;  of  various  elements,  31,  32 

Australia,  and  monsoon  winds,  107 ;  hottest  and  coldest  places  in,  280 

BACTERIA,  and  putrefaction  diminish  with  elevation  and  over  seas,  10 ; 
absence  of,  at  high  altitudes,  43 ;  gathered  by  snow,  ice,  and  water, 
43 ;  destroyed  by  sunshine,  248 

Balloon,  use  of,  in  meteorological  research,  19 ;  record  of  temperatures 
at  high  altitudes  by,  124,  210-212 

Barometer,  discovered  by  Torricelli,  23;  aneroid,  66;  forecasting 
weather  with  the  aneroid,  74-79 ;  table  for  forecasting  weather  by, 
76 ;  discovery  of  principle  of,  77-79 ;  effect  of  storms  on,  79 ;  low 
at  Poles,  103 ;  data  from,  in  meteorological  science,  292,  293 

Bathing,  fresh  and  salt  water,  249 

Berlin,  Germany,  temperature  of  earth  at  great  depth  at,  179 ;  Christmas 
Day  in,  271 

Bermuda,  sub-permanent  Highs  and  Lows  in  region  of,  159; 
251 ;  climate  of,  compared  with  Florida  and  California,  256-261 ; 
author's  visit  to,  257;  range  of  thermometer  in  Hamilton,  257; 
wind  velocity  and  humidity  in,  257,  258 ;  charm  of,  258 ;  location 
of,  258 ;  influence  of  ocean  on  climate  of,  258,  259 ;  character  of 
islands  of,  259,  260 ;  flowers  in,  260 ;  wind  and  rainfall  in,  261 ;  me- 
teorological statistics  for,  264 


INDEX  311 

Bethlehem  of  Judea,  Christmas  Day  in,  268,  269 

Bismuth,  nucleus  of  atom  of,  32 

Blair,  Major  William  R.,  on  air  travel,  27 

Boiling  point  of  water,  57,  58 ;  as  a  gauge  for  altitude,  60,  61 

Bombay,  India,  Christmas  Day  in,  272 

Boston,  Mass.,  influence  of  ocean  on  summer  temperature  of,  194 

Bowie,  E.  H.,  National  Forecaster,  rules  for  forecasting,  151-153 

Brazil,  high  temperature  in  interior  of,  278 

CAIRO,  EGYPT,  Christmas  Day  in,  272 

Calcutta,  India,  Christmas  Day  in,  272 

California,  summer  temperature  of  coast  of,  194 ;  wet  and  dry  seasonal 
records  in  big  trees  of,  236,  237;  climate  of  Bermuda  compared 
with  that  of,  256-261 

Calms,  belt  of,  at  equator,  99 

Calorie.    See  GRAM-CALORIE 

Cape  Town,  South  Africa,  Christmas  Day  in,  274 

Carbon,  nucleus  of  atom  of,  31 

Carbon  dioxide,  in  atmosphere  of  earth,  5 ;  one  of  earth's  atmospheres, 
29 ;  functions  of,  35-37 ;  seasonal  proportions  of,  in  air,  35 ;  pro- 
portions of,  according  to  locality,  35 ;  injurious  proportion  of,  35, 
36 ;  reaches  maximum  at  night  over  land,  36 ;  dissolved  in  sea  water, 
36 ;  maximum  at  midday  over  oceans,  36 ;  density  of,  36 

Carbonic  acid  gas.     See  CARBON  DIOXIDE 

Carnegie  Foundation,  investigation  of  big  trees  in  California,  236,  237 

Caspian  Sea,  waters  of,  have  receded,  235 ;  again  advancing,  235,  236 

Centers  of  Action,  101 ;  permanent  Highs  and  Lows  in  Pacific  Ocean  are 
great,  158 ;  influence  of  certain,  on  climate,  192-194 

Centigrade  scale,  compared  with  Fahrenheit,  67,  68 

Central  America,  changes  of  climate  in,  238 

Change  of  climate,  mistaken  ideas  of,  225-230;  importance  of,  to  sub- 
arid  West,  229 ;  in  period  of  authentic  history,  233,  234 ;  in  United 
States,  235 ;  simultaneous  in  Europe  and  America,  237 ;  east  and 
west,  opposite  in  character  from  north  and  south,  237,  238;  in 
Central  America,  238;  in  middle  latitudes,  239;  in  prehistoric 
times,  239 ;  as  recorded  by  geology,  239 ;  shown  by  fossil  remains, 
239 ;  and  civilization,  240 ;  author's  views  on,  242,  243 

Chautauqua  lectures,  author's  views  on  change  in  climate  in,  242,  243 

Chemical  rays,  a  manifestation  of  solar  energy,  49 ;  of  light,  52 

China,  Christmas  Day  in,  272,  273 

China  Sea,  and  monsoon  winds,  106 

Chinook  winds,  107 

Christmas  in  many  climes,  266-275 

Circulation  of  air,  55;   general,  of  wind,  98-111 

Cirrus  clouds,  288 

Civilization,  influence  of  climate  on,  213-224 ;  mistaken  idea  of  change 


312  INDEX 

Civilization,  continued 

of  climate  and,  229;  must  migrate  with  shifting  of  climatic  belts, 
240 

Cleveland,  President  Grover,  appoints  Prof.  Moore  chief  of  Weather 
Bureau,  306 

Climate,  161-187;  difference  between  weather  and,  161;  changes  in, 
161;  how  it  is  modified  and  controlled,  188-212;  its  influence  on 
civilization,  213-224;  has  our,  changed?  225-244;  influence  of 
forests  on,  240-244 ;  controlling  factors  of  American,  243,  244 ;  how 
to  find  the,  you  seek,  249-252;  of  Cuba,  252,  253;  of  Porto  Rico, 
253,  254 ;  of  the  Hawaiian  Islands,  254,  255 ;  of  the  Philippines, 
255,  256 ;  of  Bermuda  compared  with  Florida  and  California,  256-261 

Climates  for  health  and  pleasure,  245-281 

Climatic  conditions,  optimum  of,  favorable  to  man,  218,  219 

Cloud,  temperature  as  affected  by,  172 ;  formation  and  composition  of, 
287,  288 ;  difference  between  mist,  rain,  fog,  and,  288 ;  fundamental 
formations  of,  288 ;  characteristics  of  the,  formations,  288 ;  fog  is, 
at  a  low  level,  288 

Cold,  contraction  of  air  by,  15 ;  development  of  man  favored  by,  climate, 
224 ;  severest :  in  North  America,  277,  278 ;  in  South  America,  278 ; 
in  Europe,  279 ;  in  Asia,  280 

Coldest  and  hottest  places  in  the  world,  275-281 

Cold  storage,  efficient  underground,  183,  184 

Cold  wave,  scavenger  of  the  air,  36,  37 ;  beneficial  effects  of,  37 ;  great 
eddies  in  atmosphere,  118 ;  and  speed  of  storm  movement,  123-126 ; 
formation  of,  124 ;  movement  of,  125,  126 ;  detecting  approach  of, 
125 ;  limitations  on  extent  of,  126 ;  warnings  of,  by  Bureau,  126, 
127;  definition  of,  127,  128;  maps  showing  zones  of,  127,  128; 
number  of,  128,  129;  tempered  by  Great  Lakes,  129,  130;  tem- 
pered by  heat  of  large  cities,  130,  131 ;  influenced  by  Rocky  Moun- 
tain Divide,  131 ;  Weather  Bureau  warnings  of,  301,  302 

Colorado  Desert,  Cal.,  extreme  heat  in,  277 

Columbus,  Christopher,  and  the  trade  winds,  102 

Combustion,  rapid  in  liquid  air,  9 ;  nitrogen  will  not  support,  33 ;  and 
oxygen,  34 

Commerce,  benefits  of  Weather  Bureau  service  to,  301,  302 

Condensation,  and  variations  in  temperature,  163,  164,  282-290 

Congelation,  174 

Constantinople,  Turkey,  Christmas  Day  in,  271 

Continents,  circulation  between  oceans  and,  105 ;  their  influence  on  cli- 
mate, 192-198;  characteristics  of  temperature  of  interior  of,  194. 
195 

Contour  of  land,  and  frost,  86-97 

Convection,  and  heat,  54,  55 

Copper,  nucleus  of  atom  of,  32 

Coronas,  141 


INDEX  313 

Cox,  Prof.  J.  H.,  and  observations  on  frost,  93,  94 

Cranberry  bogs,  and  frost,  93-95 

Crime,  influence  of  weather  conditions  on,  215 

Cuba,  climate  of,  252,  253 

Cultivation  of  land  surface,  and  frost,  93-95 

Cumulus  clouds,  288 

Gushing,  comparison  of  temperatures  by,  196,  197,  215 

Cyclone,  general  cause  of,  98 ;  general  whirl  of,  103 ;  gyration  of,  107- 
109;  the  disk  of  air  constituting  a,  119;  an  area  of  low  pressure, 
119 ;  action  of  the  air  in  and  around  the,  120 ;  movement  of  the,  120 ; 
general  extent  of,  141 ;  destructive  force  of,  142 

Cyclones,  localities  in  which,  are  formed,  156,  157 

DAWSON,  CANADA,  annual  range  of  temperature  at,  169 

Death  rate,  excessive  humidity  increases,  216,  217 

Death  Valley,  Cal.,  intense  heat  in,  275-277;  area  and  forbidding 
character  of,  276 ;  temperature  records  taken  in,  276,  277 

Deflection,  due  to  earth's  rotation,  107 

Density  of  earth's  atmosphere  at  different  levels,  6 

"  Descriptive  Meteorology,"  141;  reasons  for  change  of  opinion  on 
change  of  climate  expressed  in,  233 

Desert  of  Sahara,  Africa,  intense  heat  in,  279 

Dew  point,  38 ;  and  frost,  89.  90 

Diathermancy,  56 ;  124 

Dirigible  balloon,  as  competitor  of  railroad,  19 ;  importance  of  develop- 
ing the,  27 

Disease,  elevation  diminishes  bacteria  of,  10;  amelioration  of,  by  sun- 
shine, 248 

Drainage,  influence  on  frost,  94 

Droughts,  the  breaking  of,  136 

Dunwoody,  Brig.  Gen.  H.  H.  C.,  expert  forecaster  and  chief  of  Weather 
Bureau,  306 

Dust,  in  the  atmosphere,  33 

Dust  motes,  absence  of,  at  higher  altitudes,  9;  interference  of  sun's 
rays  by,  10;  source  of,  43,  44;  vary  according  to  locality,  44; 
counting  of,  44,  45 ;  and  diffusion  of  light,  45,  46 ;  and  twilight,  46, 
47 

EADS  BRIDGE,  ST.  Louis,  freak  of  tornado  and  the,  147 
Earth,  early  condition  of,  1 ;  death  of,  due  to  lack  of  heat  from  sun,  3, 
4 ;  early  condition  of  atmosphere  of,  5 ;  transmission  of  sun's  rays 
to,  7,  8 ;  water  vapor  in  atmosphere  of,  8 ;  four  atmospheres  of  the, 
29-47 ;  comparison  of  heat  of  sun  and  of,  48 ;  circulation  of  winds 
and  rotation  of,  98-111;  deflection  of  winds  due  to  rotation  of, 
107-109;  conditions  if  axis  of,  were  vertical,  164;  variations  of 
heat  of  morning,  midday,  and  evening,  166 ;  change  of  seasons  and 


314  INDEX 

Earth,  continued 

the,  166;  percentage  of  solar  rays  reaching  the,  166-168;  lag  of 
temperatures  of  the,  168;  kept  from  freezing  by  water  vapor,  170; 
how  the,  cools  at  night,  171,  172 ;  great  heat  of  interior  of  the,  178, 
179 ;  a  poor  reflector,  conductor,  and  radiator,  179 ;  temperatures  at 
various  depths  in  the,  179 ;  warmer  than  air  next  above,  180 ;  con- 
ditions if,  were  all  land,  188-190;  if  axis  of,  were  perpendicular  to 
plane  of  orbit,  188,  189;  conditions  if,  were  all  water,  190-192; 
the  real,  of  land,  water,  and  inclined  axis,  192 

Eclipse,  study  of  sun's  atmosphere  during,  2 

Efficiency,  weather  conditions  and  human,  216 ;  maximum  and  minimum 
periods  of  human,  217,  218 

Electricity,  and  atoms,  31 ;  a  manifestation  of  solar  energy,  49 

Electron,  nucleus  of  all  atoms,  31 

Elements,  nuclei  of  atoms  of  various,  31,  32 

England,  second  nation  to  establish  weather  service,  297 

Equator,  circulation  of  wind  and  temperature  at,  99 ;  belt  of  calms  at,  99 

Equatorial  currents,  202,  203 

Equinoctial  storm,  140 

Equinox,  significance  of,  140 

Equinoxes  (Fig.  21),  163 

Espy,  James  P.,  his  theory  of  continuation  of  storms,  156 ;  296 

Ether,  in  outer  space,  7 ;  transmission  of  sun's  rays  by,  7,  8 ;  interstellar 
space  filled  with,  48 ;  man's  ignorance  of  structure  of,  48 ;  transmis- 
sion of  solar  energy  through,  49 

Eurasia,  cooling  of  continent  of,  in  winter,  106 ;  extremes  of  tempera- 
ture in  continent  of,  195-197 

Europe,  sections  of,  where  climatic  conditions  are  best,  245;  hottest 
and  coldest  places  in,  279 

Evaporation,  58,  59 ;  cooling  effects  of,  74 ;  and  frost,  92 ;  lowers  tem- 
perature of  wet  soil,  180 

FAHRENHEIT  SCALE,  compared  with  Centigrade,  67,  68 

Floods,  influence  of  forests  on,  240-244 ;  flow  of,  not  restricted  by  forests, 
244 

Florida,  climate  of  Bermuda  compared  with  that  of,  256-261 

Fog,  formation  of,  92,  288 ;  and  frost,  92 ;  temperature  as  affected  by,  172 

Fb'hn  winds,  107 

Forecasting,  general  rules  for,  149-153;  importance  of  use  of  weather 
map  in,  149 ;  the  temperature  by  amateurs,  149,  151 ;  expectations 
of  future,  303,  304 ;  fake,  304 

Forests,  exaggerated  idea  of  influence  of,  on  climate,  198,  200;  their 
influence  on  climate  and  floods,  240-244 ;  the  author's  opinion  on, 
241 ;  as  conservers  of  rainfall,  241 ;  mistaken  idea  of  value  of,  as 
conservers,  243 ;  need  of  protection  of,  243 ;  restrict  flow  of  moder- 
ate rainfall  but  not  floods,  244 


INDEX  315 

Fossil  remains,  as  evidence  of  changes  of  climate,  239 
France,  third  nation  to  establish  weather  service,  297 
Franklin,  Benjamin,  his  study  and  theory  of  storm  movements,  293-296 
Freezing,  of  fresh  and  salt  water,  173-175 ;  height  of,  cold  in  free  air,  185 
Frost,  85-97 ;   causes  of  formation  of,  85 ;   light,  heavy  and  killing,  86 ; 
dew  point  in  relation  to,  89,  90 ;    black,  90 ;    locality  and  immunity 
from,  90,  91 ;  conditions  conducive  to,  91 ;    Weather  Bureau  obser- 
vations on,  91,  92;   evaporation  and,  92;    cultivation  of  land  sur- 
face and,  93-95 ;  effect  of  sand  covering  on,  94,  95 ;  dates  of  killing, 
spring  and  fall,  96,  97 ;  287 
Fuel,  proper  humidity  and  conservation  of,  73,  74 

GALILEO,  and  the  thermometer,  23,  292,  293 

Gases  of  the  atmosphere,  in  mechanical  not  chemical  union,  32 ;  impor- 
tance of  proper  proportions  of,  32 

Geology,  evidence  of  changes  of  climate  given  by,  239 

Germs,  in  the  atmosphere,  33 

Glacial  periods,  239 

Glaciers,  movement  of,  60 ;  recession  and  advancement  of,  239 

Glashier,  English  meteorologist,  balloon  ascension  by,  20 

Gold,  nucleus  of  atom  of,  32 

Gram-calorie,  unit  of  heat,  51 

Great  Ice  Cap,  possible  return  of,  240 

Great  Lakes,  temper  severity  of  cold  waves,  129, 130 ;  benefit  of  Weather 
Bureau  service  to  mariners  on  the,  302 

Greely,  Gen.  A.  W.,  chief  of  Weather  Service,  306 

Gulf  Stream,  West  Indian  hurricanes  generally  follow  the,  133,  201 ;  in- 
fluence of,  on  climate,  202,  203;  source  and  course  of,  202,  203; 
individuality  of  the,  203 ;  has  no  effect  on  climate  of  Bermuda,  258, 
259 

Gyration,  due  to  earth's  rotation,  108,  109 

HAIL,  formation  of,  287 ;  and  thunderstorms,  287 ;  attempted  preven- 
tion of,  290 

Hailstones,  foreign  matter  hi,  284 ;  formation  and  size  of,  287 

Halos,  cause  and  nature  of,  140,  141 ;  lunar,  141 

Harrington,  Prof.  Mark  W.,  first  chief  of  new  civil  Weather  Bureau,  306 

Havana,  Cuba,  climate  of,  253 

Hawaiian  Islands,  climate  of  the,  254,  255 

Haze,  nature  and  characteristics  of,  282 

Hazen,  Brig.  Gen.  William  B.,  chief  of  Weather  Service,  306 

Health,  north  winds  conducive,  south  winds  detrimental  to,  26;  tem- 
perature in  its  relation  to,  216 ;  semi-annual  maximum  and  minimum 
periods  of,  217,  218 

Health-seeker,  all-the-year  climate  for  the,  252 

Heat,  expansion  of  air  by,  15 ;  possibility  of  using  earth's  interior,  18 ; 


316  INDEX 

Heat,  continued 

how  it  reaches  the  earth,  46 ;  source  of,  49 ;  of  sun  and  earth  com- 
pared, 48;  manifestation  and  transmission  of,  48,  49,  51 ;  difference 
between  temperature  and,  49,  50 ;  commercial  and  scientific  unit  of, 
50,  51 ;  difference  between  waves  of  light,  sound,  and,  51 ;  conduction 
of,  54 ;  radiation  of,  54 ;  convection  of,  54,  55 ;  absorption  of,  55, 
56;  specific,  56;  latent,  56-58;  differing  temperatures  with  same 
solar,  162-166 ;  great  capacity  of  water  for,  200,  201 ;  ocean  cur- 
rents distributors  of,  201,  202;  extreme,  in  Death  Valley  and  Colo- 
rado Desert,  275-277 ;  in  South  America,  278 ;  in  Africa,  279 ;  in 
Europe,  279 ;  in  Asia,  279,  280 ;  in  Australia,  280 

Heat  rays,  absorption  of  sun's,  8 

Heat  waves,  difference  between  light,  sound,  and,  51 ;  length  of,  51 

Helium,  in  earth's  atmosphere,  5,  6 ;  importance  of  manufacture  of,  19 ; 
nucleus  of  atom  of,  31 

Henry,  Prof.  Joseph,  compiles  first  weather  map,  296 

Hersey,  Lieut.  Col.  Henry  B.,  on  dirigibles  and  airplanes,  28 

High-pressure  belts,  rains  of  the,  105 

Highs,  initiation  of,  101 ;  placing  of,  on  weather  map,  115,  116;  charac- 
teristics of,  124 ;  conditions  and  action  of  air  of,  131-133 ;  perio- 
dicity of,  132;  and  warm  waves,  136;  influence  of  certain,  on  cli- 
mate, 192-194 

Himalaya  Mountains,  and  monsoon  winds,  106,  206;  and  climate  of 
Asia,  206 ;  rainfall  in  the,  206 

Holland,  establishes  first  weather  service,  297 

Holy  Land,  formerly  an  abundance  of  water  in,  235 

Honolulu,  Hawaii,  climate  of,  254 

Hottest  and  coldest  places  in  the  world,  275-281 

Human  energy,  climate  and  the  distribution  of,  220 

Humboldt,  Baron  von,  on  civilization  and  climate,  214 

Humidifiers,  72 

Humidity,  percentage  expression  of  relative,  38, 39 ;  absolute,  39 ;  68-74 ; 
tables  of  relative,  69-71 ;  importance  of  proper,  in  living  quarters, 
72 ;  diseases  due  to  lack  of,  73 ;  and  conservation  of  fuel,  73,  74 ; 
excessive,  harmful  to  man,  216,  217 ;  proper  percentage  of,  217 

Huntington,  Ellsworth,  comparison  of  temperatures  by,  196,  197;  215; 
on  human  energy,  217,  218 ;  on  examination  of  big  trees  in  Califor- 
nia, 236,  237 

Hurricane,  West  Indian,  133,  134 ;  the  Galveston,  134 ;  nature  and  de- 
velopment of,  134, 135 ;  exposure  of  Atlantic  coast  to  effects  of,  135, 
136 

Hurricanes,  general  extent  of,  141 

Hydrogen,  in  earth's  atmosphere,  5,  6 ;  nucleus  of  atom  of,  31 ;  and 
oxygen  combined  to  form  water,  32;  density  of,  39;  combustible 
properties  of,  39 ;  sources  of  supply  of,  39,  40 

Hygrometer,  for  measuring  water  vapor,  39 


INDEX  317 

ICE,  and  bacteria,  43;    formation  of,  43;    specific  heat  of,  56;    latent 

heat  of  melting,  57 ;  melting  of,  under  pressure,  60 
Ice  ages,  239 

Ice  Cap,  possible  return  of  Great,  240 
Iceland,  sub-permanent  Highs  and  Lows  in  region  of,  159 
Inclosed  seas,  temperature  of  waters  of,  176-178 ;   latitude,  season  and 

depth  change  temperature  of,  177,  178 
Indian  Ocean,  and  monsoon  winds,  106,  107 ;  temperature  of  waters  of, 

176 

Industry,  benefits  of  Weather  Bureau  service  to,  301,  302 
Instrument  shelter,  66-68 
Instruments,  in  meteorological  stations,  63 ;  for  voluntary  observer,  66- 

79 

Invisible  light,  52,  53 
Iron,  nucleus  of  atom  of,  32 
Isobars,  on  weather  map,  115 

Isothermal  lines,  ocean  currents  and  changes  in,  201,  202 
Isothermal  stratum,  height  of,  11;  temperature  of,  11,  12;  211 

JACKSONVILLE,  FLA.,  meteorological  statistics  for,  263 

Japan,  Christmas  Day  in,  273 

Jefferson,  Thomas,  on  the  changing  climate,  227 ;    records  of  readings 

of  thermometer  by,  232 ;    barometrical  records  of,  233 ;    loss  of  his 

barometer,  233 ;   weather  observations  by,  296 
Jupiter,  atmosphere  of,  3 ;  and  heat  from  sun,  3 
Justice,  weather  records  serve  ends  of,  79-83 

KANSAS  CITY,  Mo.,  climate  of,  210 

Kelvin,  Lord,  on  the  size  of  molecule  of  water,  30 

Kites,  in  meteorological  research,  19;   use  of,  by  Weather  Bureau,  22; 

rectangular  form  of,  22 ;   observations  from,  64 ;   construction  and 

flying  of,  64-66 

Krakatoa,  effects  of  eruption  of,  43,  44 
Krypton,  33 

LAKE  OWENS,  CAL.,  waters  of,  have  receded,  235 

Lake  Superior,  temperature  of  waters  of,  178 

Lakes,  influence  of,  on  climate,  199,  200 

Lapham,  Dr.  I.  A.,  298 ;  urges  establishment  of  weather  service,  305 

Latent  heat,  56-58 

Latitude,  its  relation  to  health,  strength,  and  efficiency  of  man,  218 

Lead,  nucleus  of  atom  of,  32 

Life,  the  atmosphere  in  relation  to  beginnings  of,  2,  3;    thinness  of 

stratum  of  air  that  sustains,  14 ;  how  to  prolong,  246 ;  in  the  open 

air  and  sunshine,  247-249 
Light,  slight  refraction  of,  in  higher  altitudes,  9 ;  diffused  by  dust  motes. 


318  INDEX 

Light,  continued 

45 ;  source  of,  49 ;  how  it  reaches  the  earth,  49 ;  a  manifestation 
of  solar  energy,  49 ;  invisible,  52,  53 ;  and  transparency,  56 ;  speed 
of,  162 ;  from  the  stars,  162 

Light  waves,  difference  between  heat,  sound,  and,  51 ;  length  of,  51 ; 
velocity  of,  51,  52;  and  invisible  light,  52,  53 

Lining,  Dr.  John,  temperature  records  kept  by,  293 

Liquid  air,  9 

Local  forecasting,  rules  for  making,  153-155 

Lofoten  Islands,  temperatures  recorded  in  the,  196 

London,  England,  Christmas  Day  in,  269,  270 

Loomis,  Elias,  296 

Los  Angeles,  Cal.,  climate  of,  210 ;  meteorological  statistics  for,  262 

Lows,  the  initiation  of,  101;  placing  of,  on  the  weather  map,  115,  116; 
characteristics  of,  124;  their  influence  on  cold  waves,  126;  con- 
ditions and  action  of  air  of,  131-133;  periodicity  of,  132;  and 
warm  waves,  136 ;  V-shaped,  137 ;  influence  of  certain,  on  climate, 
192-194 

Lunar  halos,  141 

MACREADT,  LIEUT.  JOHN  A.,  altitude  record  of,  20 

Mammoth  Cave,  temperature  of,  181 

Man,  climate  and  the  dominant  races  of,  213-224;  conditions  best 
suited  to  health,  strength,  and  efficiency  of,  215,  216 ;  excessive  hu- 
midity harmful  to,  216,  217;  semi-annual  maximum  and  minimum 
periods  of  efficiency  of,  217,  218 

Manila,  P.  I.,  climate  of,  255  ; 

Maritime  interests,  benefits  of  Weather  Bureau  service  to,  300-303 

Marvin,  Prof.  Charles  F.,  present  chief  of  Weather  Bureau,  306 

Matter,  early  belief  as  to  construction  of  all,  30 ;  present  knowledge  of 
nature  of,  31 ;  determination  of  differences  in,  31 ;  forms  of  simple,  31 

Maury,  Matthew  F.,  298 

Mazatlan,  Mexico,  climate  of,  209 

Mediterranean  Sea,  temperatures  of  waters  of,  177 

Melbourne,  Australia,  Christmas  Day  in,  275 

Mental  activities,  and  weather  conditions,  215,  216 

Mercury,  density  of,  compared  to  air,  15 ;  nucleus  of  atom  of,  32 

Mesopotamia,  former  fertility  of,  234,  235 

Meteorological  conditions  best  suited  to  efficiency  of  man,  216 

Meteorological  science,  in  America,  291-306.  See  also  UNITED  STATES 
WEATHER  BUREAU 

Meteorological  station,  instruments  installed  in,  63 

Meteorological  statistics,  tables  of :  for  Los  Angeles,  Cal.,  262 ;  for  Mi- 
ami, Fla.,  262;  for  Jacksonville,  Fla.,  263;  for  San  Diego,  Cal., 
263 ;  for  Tampa,  Fla.,  264 ;  for  Bermuda,  264 

Meteorologists,  association  of  aviator  with,  in  map  making,  23 ,, 


INDEX  319 

Meteors,  cause  of  luminosity  of,  6 

Meyer,  Gen.  Albert  J.,  inaugurates  tentative  weather  service,  305 

Mexico  City,  climate  of,  209,  210 

Miami,  Fla.,  temperature  and  rainfall  at,  261 ;  meteorological  statistics 
for,  262 

Microbes  of  the  air,  41-43 ;  functions  of  the  useful  varieties  of,  41,  42 ; 
and  locality,  42 ;  and  crowded  habitations,  42 ;  effect  of  sunshine 
on,  42,  43 ;  dust-free  air  free  of,  44 

Milwaukee,  Wis.,  rules  for  forecasting  at,  153-155 

Mind,  effects  of  weather  conditions  on*  215 

Mock  moon,  141 

Mock  sun,  141 

Molds,  destroyed  by  sunshine,  248 

Molecule,  infinitesimal  size  of,  of  air  and  of  water,  29,  30 ;  of  raindrop, 
282,  283 

Molecules,  space  between,  of  gases,  29 

Monsoon  winds,  106,  107 

Moon,  a  dead  planet,  4 ;  absence  of  atmosphere  around,  4,  5 ;  tempera- 
ture of  dark  side  of,  5;  has  no  influence  on  weather,  138-140;  and 
the  tides  of  the  ocean,  139 ;  no  influence  on  crops,  140 ;  and  halos, 
141 ;  mock,  141 

Moore,  Prof.  Willis  L.,  experience  at  Chautauqua  lectures,  19 ;  predic- 
tion of  trans-oceanic  flight  by  airplane,  19,  20;  experiments  with 
small  gas  balloons,  21 ;  appointed  chief  of  Weather  Bureau,  306 ; 
long  service  as  chief,  306 ;  removal  of,  306 

Moscow,  Russia,  Christmas  Day  in,  273 

Mountain  air,  beneficial  effects  of,  249,  250 

Mountains,  why  peaks  of,  are  cold,  8,  171 ;  effect  of,  on  climate,  204-206 ; 
and  rain  and  snow,  205,  206 

Mount  Weather,  Va.,  research  work  at,  21,  22;  value  of  work  at,  in 
World  War,  24,  25;  altitude  record  of  temperature  at,  211, 
212 

Munich,  Bavaria,  record  of  earth's  temperatures  at,  168 

NEON,  33 

Neptune,  atmosphere  of,  3 ;  and  heat  from  sun,  3 

New  Bedford,  Mass.,  daily  weather  records  for  long  period  at,  228 

New  York,  N.  Y.,  influence  of  ocean  on  summer  temperature  of,  194 

Nimbus  clouds,  288 

Nitric  acid,  33 

Nitrogen,  in  atmosphere  of  earth,  8;    one  of  earth's  atmospheres,  29; 

nucleus  of  atom  of,  31 ;  debilitating  effects  of,  32 ;  functions  of,  33 ; 

absence  of,  above  fifty  miles,  212 
North  America,  and  monsoon  winds,  107;   hottest  and  coldest  places 

in,  275-278 
"Northwester",  cause  of,  117 


320  INDEX 

OBSERVATIONS,  great  number  and  vast  area  covered  by  Weather  Bureau, 
298.  See  also  WEATHER  OBSERVATIONS 

Ocean,  intense  cold  at  bottom  of,  175,  176 ;  temperature  of  inclosed  seas 
differ  from  those  of,  176,  177 ;  temperatures  of  Atlantic,  177 ;  lati- 
tude, season  and  depth  changes  temperatures  of,  177,  178 ;  direction 
of  wind  affects  shore  temperature  of,  178 ;  influence  of,  on  climate, 
192-198 ;  climate  of  Bermuda  controlled  by,  258,  259 

Ocean  currents,  influence  of,  on  climate,  200-202;  circulation  of,  fol- 
lows winds,  200-202;  great  distributors  of  heat,  201,  202 

Oceans,  circulation  between  continents  and,  105 

"Oldest  Inhabitant",  hallucinations  of,  as  to  weather,  225-228 

Open  air,  life  in  the,  247-249 

Organic  matter,  in  atmosphere,  33 

Oxygen,  in  atmosphere  of  earth,  8;  and  liquid  air,  9;  one  of  earth's 
atmospheres,  29 ;  nucleus  of  atom  of,  31 ;  stimulating  effect  of,  32 ; 
union  of,  with  hydrogen  to  constitute  water,  32;  functions  of,  33- 
35 ;  proportion  of,  in  free  air,  34 ;  in  places  with  restricted  ventila- 
tion, 34 ;  necessary  to  life,  35 ;  causes  of  decrease  of,  37 ;  ozone  is 
highly  electrified,  40 ;  absence  of,  above  thirty  miles,  212 

Ozone,  33;  source  of,  40;  characteristics  of,  40;  effects  of,  40,  41; 
variation  of,  due  to  seasons  and  locality,  41 ;  effects  of  winds  on,  41 

PARIS,  FRANCE,  Christmas  Day  in,  270  • 

Permanent  Highs  and  Lows  in  the  Pacific,  great  Centers  of  Action,  158 ; 

interference  with  storms  from  Orient  by,  158 
Petrograd,  Russia,  Christmas  Day  in,  273 
Philippine  Islands,  climate  of  the,  255,  256 
Pittsburgh,  Pa.,  climate  of,  210 
Planets,  quicker  cooling  of  the  small,  2 ;  lifeless,  2,  3 
Plant  life,  necessity  of  oxygen  to,  35 ;  carbon  dioxide  and,  35 
Poles,  temperature  and  circulation  of  wind  at  the,  99 ;   barometer  low 

at,  103 ;  not  the  coldest  points  in  the  world,  280 
Population,  storm  tracks  and,  214-223 
Porto  Rico,  climate  of,  253,  254 
Precipitation,  factors  controlling,  of  a  region,  230 
Pressure,  difference  between,  and  weight  of  air,  77;    belt  of  high,  at 

latitudes  30°  north  and  south,  99,  101 ;   indicated  on  weather  map 

by  Highs  and  Lows,  115,  116 

"Principles  of  Human  Geography  ",  196,  215 ;  quoted,  219,  220 ;  236,  237 
Putrefaction,  bacteria  of,  diminish  with  elevation,  10 

RACES  OF  MAN,  climate  and  the  dominant,  213-224 

Radiation,  earth,  8 ;   of  heat,  54 ;   and  frost,  85-97 ;   and  circulation  of 

wind,  98 ;  earth  and  air  cooled  by,  171 ;  and  temperature  of  valleys, 

203,  204 
Radium,  nucleus  of  atom  of,  32 


INDEX  321 

Raindrops,  size  and  composition  of,  282 ;  falling  or  evaporation  of,  283 ; 
where,  are  formed,  283;  what  causes,  284;  cannot  form  at  great 
altitudes,  284;  velocity  of  falling,  284,  285;  air  retards  falling, 
285 

Rainfall,  cause  of  heavy,  in  tropics,  104,  105 ;  monsoon  winds  and  heavy, 
106;  in  Himalaya  Mountains,  206;  average  monthly,  in  North 
America  and  in  the  Old  World,  207-210;  forests  as  conservers  of, 
241 ;  in  Hawaiian  Islands,  255 ;  instantaneous  precipitation  of  all 
water  vapor  and,  285 ;  causes  of  heavy,  285 

Rain  making,  artificial,  288,  289 

Rain  water,  pure  when  condensed,  284;  collects  impurities  in  falling, 
284 

Redfield,  296 

Red  Sea,  temperatures  of  waters  of,  176 

Reflection,  water  rejects  heat  by,  172 

Refrigerator,  an  economical,  59 

Relative  humidity,  tables  of,  69-71 

Rio  de  Janeiro,  Brazil,  Christmas  Day  in,  274 

Rivers,  influence  of,  on  climate,  199,  200 

Rocky  Mountains,  influence  on  cold  waves  by  the,  131 ;  effects  of  reduc- 
tion in  height  of,  230-232 ;  records  inscribed  by  waters  on,  234,  235 

Rome,  Italy,  Christmas  Day  in,  272 

Rotation  of  earth,  deflection  caused  by,  107-109 

Russia,  Christmas  Day  in,  273 

ST.  Louis,  Mo.,  tornado  of  1896  in,  146-148 

St.  Paul,  Minn.,  climate  of,  210 

Salt,  in  atmosphere,  33 

Samoa,  annual  range  of  temperature  in,  169 

Sand,  as  a  preventive  of  frost,  94,  95 

San  Diego,  Cal.,  lowest  temperature  recorded  at,  129;  meteorological 
statistics  for,  263 

Sanitaria,  250 

San  Juan,  Porto  Rico,  climate  of,  253,  254 

Santiago,  Chili,  Christmas  Day  in,  274 

Saturation,  point  of,  38;  dew  point  and,  38;  varies  according  to  tem- 
perature of  air,  38,  39 

Saturn,  atmosphere  of,  3 ;  and  heat  from  sun,  3 

Schroeder,  Major  R.  W.,  11 ;  altitude  record  of,  20;  experience  of,  20 

Scientific  American,  The,  on  statistics  of  climate,  265,  266 

Sea  air,  beneficial  effects  of,  249 

Seasons,  cause  of  change  of,  166-168;  reversal  of,  in  the  northern  and 
southern  hemispheres,  169;  conditions  resulting  in  no,  188,  190; 
forces  that  influence  and  control  the,  188-190 

Silver,  nucleus  of  atom  of,  32 ;  best  conductor  of  heat  among  the  metals, 
54 


322  INDEX 

Sleet,  snow  and  the  formation  of,  286,  287 

Smith,  Robert  Angus,  on  carbon  dioxide,  34,  36 

Smithson,  James,  297 

Smithsonian  Institution,  296 ;  activities  in  practical  meteorology,  297 

Snow,  water  vapor  in  congealed  form,  285 ;  beauty  and  variety  of  crys- 
tals of,  286 ;  and  the  formation  of  sleet,  286,  287 

Solar  energy,  transmission  of,  through  the  ether,  49 

Solids,  heat  expands  most,  59 

Solstices  (Figs.  22  and  23),  summer  and  winter,  164;   (Fig.  26),  167 

Sound  waves,  difference  between  heat,  light,  and,  51 ;  length  of,  51 ; 
velocity  of,  51,  52 

South  America,  and  monsoon  winds,  107 ;  hottest  and  coldest  places  in, 
278 

Space,  ether  in  outer,  7,  48 ;  temperature  of  outer,  9 ;  darkness  of  outer, 
9 ;  the  proof  of  lack  of  light  in,  9,  10 ;  transmission  of  heat  through, 
48 ;  absence  of  atmosphere  in,  48 

Stars,  size  of,  and  distance  from  earth,  162 

Statistics,  tables  of  meteorological,  262-264;  The  Scientific  American 
on  climate,  265,  266 

Steel,  bums  in  liquid  air,  9 

Storm,  in  winter  of  1893,  117-123;  Franklin's  study  and  theory  of, 
movements,  293-296 ;  abnormal  movement  of  some,  centers,  300 

Storms,  terrible  nature  of,  in  early  history  of  creation,  1 ;  general  rules 
for  forecasting,  75-79;  general  action  of,  115;  great  eddies  in  at- 
mosphere, 118;  movement  of,  118,  119;  cold  waves  as  affecting 
speed  of,  123-126;  locality  of  origin  of  majority  of  our,  132;  gen- 
eral movement  of,  133 ;  equinoctial,  140 ;  tornadoes,  141-148 ;  and 
their  relation  to  density  of  population,  220-223 ;  ten-year  record  of, 
221,  222;  area  and  movement  of  cyclonic,  231 ;  Weather  Bureau's 
study  of  types  of,  299,  300;  peculiar  action  of  barometer  in  some 
types  of,  299,  300 ;  Weather  Bureau  detects  inception  of,  302  ;  fre- 
quency of,  304 

Storm  tracks,  civilization  follows  the,  213-224 

Stratus  clouds,  288 

Strength,  temperature  and  its  relation  to  physical,  216 

Sub-permanent  Highs  and  Lows,  158;  of  the  Pacific  a  bar  to  storms 
from  the  Orient,  158 ;  effect  of  change  of  position  of,  158-160 ;  in 
the  region  of  Iceland  and  Bermuda,  159 

Sulphates,  in  atmosphere,  33 

Sulphur,  nucleus  of  atom  of,  31,  32 

Summer,  difference  in  length  of,  in  northern  and  southern  hemispheres, 
169 

Summer  resort,  an  aerial,  13,  14 

Summer  temperature  gradients  in  isothermal  stratum,  12 

Sun,  atmosphere  of  the,  2 ;  conditions  for  beginning  of  life  on  the,  2,  3 ; 
will  be  no  life  on,  3;  effect  on  earth  of  cooling  of  the,  4;  trans- 


INDEX  323 

'Sun,  continued, 

mission  of  rays  of,  by  the  ether,  7,  8 ;  absorption  by  oxygen,  nitro- 
gen, and  water  vapor  of  rays  of,  8 ;  and  twilight,  46,  47 ;  comparison 
of  heat  of  earth  and  of,  48 ;  mock,  141 ;  only  source  of  appreciable 
heat,  162 ;  earth's  orbit  around,  165 ;  cause  of  variation  in  heat  of, 
reaching  earth,  166 ;  absorption  by  atmosphere  of  rays  of,  166 

Sunshine,  life  in  the  open  air  and,  247-249 ;  destroys  molds,  248 

Supra-red  rays,  remedial  powers  of,  248 

TAMPA,  FLA.,  temperature  and  rainfall  at,  261 ;  meteorological  statistics 
for,  264 

Telescope,  agitations  of  sun's  atmosphere  revealed  by,  2 

Temperate  zone,  highest  type  of  civilization  found  in  the,  213-224 

Temperature,  of  the  isothermal  stratum,  11, 12 ;  and  water  vapor,  37,  38 ; 
difference  between  heat  and,  49,  50 ;  proper  method  of  taking,  63 ; 
and  frost,  85-97;  and  circulation  of  wind,  98-111;  red  lines  on 
map  indicate  similarity  of,  122,  123 ;  record  of,  by  balloons  at  high 
altitudes,  124 ;  how  amateurs  may  forecast,  151 ;  with  same  solar 
heat  differing,  162-166;  causes  of  variations  in,  163;  of  oceans, 
lakes,  and  rivers,  172,  173;  extremely  low,  of  ocean  bottoms,  175, 
176;  of  water  changes  with  latitude,  season  and  depth,  177;  of 
earth  at  depth  of  3490  feet,  179 ;  daily  range  of,  in  free  air,  185,  186 ; 
of  interior  of  continents,  194 ;  of  coastal  regions  influenced  by  ocean 
in  summer,  194 ;  lowest  recorded,  at  Weather  Bureau,  195 ;  highest, 
July,  195 ;  average  maximum  and  minimum,  recorded  by  Weather 
Bureau,  195 ;  extremes  of,  in  Eurasian  continent,  195-197 ;  ques- 
tionable effect  of  Gulf  Stream  on,  203 ;  influence  of  valleys  on,  203, 
204;  extremes  of,  on  mountains,  204,  205;  average  monthly,  in 
North  America  and  the  Old  World,  207-210;  at  high  altitudes, 
210-212 ;  effects  of  changes  of,  on  man,  215 ;  in  its  relation  to  health, 
strength,  and  efficiency,  215,  216 ;  and  mental  activity,  216 ;  proper 
percentage  of  humidity  and,  217 ;  the  optimum  of,  for  energy,  218, 
219 ;  regions  of  favorable,  the  summer,  250 ;  author's  record  of,  in 
Bermuda,  257 

Temperature  inversion,  171 

Temperatures,  lag  of  earth's,  168 ;  annual  range  in  air,  168,  169 ;  high- 
est and  lowest :  in  North  America,  275-278 ;  in  South  America,  278 ; 
in  Africa,  279 ;  in  Europe,  279 ;  in  Asia,  279,  280 ;  in  Australia,  280 

Thermometer,  Galileo's  discovery  of  principles  of,  23 ;  principles  and  dis- 
covery of,  62,  63 ;  comparison  of  Fahrenheit  and  Centigrade  scales 
of,  67,  68 ;  data  from,  and  meteorological  science,  293 

Thomson,  Sir  William.     See  LORD  KELVIN 

Thorium,  nucleus  of  atom  of,  32 

Thunderstorms,  effect  of,  on  Lows,  132 ;  cause,  extent  and  movement  of, 
137;  frequency  of,  138;  Highs  and,  138;  temperature  and,  138; 
Lows  and,  138 ;  locale  of,  138 ;  and  the  formation  of  hail,  287 


324  INDEX 

Tornadoes,  141-148;  extent  of,  141,  142;  velocity  and  destructive  force 
of,  142 ;  locale  of,  142 ;  frequency  of,  142 ;  rate  of  movement  and 
general  direction  of,  142 ;  warnings  of  coming  of,  142 ;  seeking  safety 
during,  142,  143;  an  American  type  of  storm,  143;  presence  of 
water  vapor  necessary  to  cause,  144;  use  of  weather  map  in  fore- 
casting, 144,  145 ;  not  increasing,  145 ;  difficulty  of  forecasting,  146, 
147;  ireaksof,  147,  148 

Toronto,  Canada,  climate  of,  210 

Torricelli,  and  the  barometer,  23,  292,  293 

Trade  winds,  101,  102 

Transparency,  56 

Tropical  zone,  cause  of  torrential  rains  in  the,  100 

Tropics,  rain  winds  of  the,  104,  105 

Tubercle  bacillus,  destroyed  by  sunshine,  248 

Twilight,  and  dust  motes,  46,  47 

ULTRA-VIOLET  RATS,  remedial  powers  of,  248 

Underground  habitations,  plan  for  unique,  180-184 

United  States,  where  climatic  conditions  are  best  in  the,  245;  fourth 
nation  to  establish  weather  service,  297 

United  States  Weather  Bureau,  experiments  with  small  gas  balloons, 
21 ;  observations  with  kites  by,  21,  22 ;  storm  warnings  by,  24 ;  and 
voluntary  observers,  66 ;  method  of  taking  readings  by,  66-79 ;  ends 
of  justice  served  by  records  of,  79-83 ;  and  prevention  of  frost,  95- 
97;  maps  prepared  by,  112-160;  timely  warnings  by,  117;  when 
warnings  are  displayed  by,  122;  warnings  of  cold  waves  by,  126, 
127 ;  definition  of  "cold  wave"  by,  127,  128 ;  and  tornado  warnings, 
146,  147;  on  forecasting,  151-153;  rules  for  forecasting  at  Mil- 
waukee, Wis.,  153-155 ;  extent  of  area  under  observation  by,  155- 
158;  comparison  of  crime  and  records  of,  215;  rainfall  records  by, 
237,  241 ;  record  of  floods  by,  241 ;  and  fake  prevention,  of 
hail,  290 ;  stations  and  observations  of  the,  291,  292 ;  fourth  national 
weather  service  established,  297 ;  the  result  of  efforts  by  American 
scientists,  298 ;  vast  area  under  daily  observation  by,  298 ;  number 
of  observations  twice  daily  by,  298 ;  first  work  of,  regarded  as  ex- 
perimental, 299;  advance  in  efficiency  of,  299;  growing  faith  in 
work  of,  299 ;  its  study  of  types  of  storms,  299,  300 ;  competitive 
examinations  held  by,  300 ;  warnings  by,  now  accepted,  300 ;  warn- 
ings of  West  Indian  hurricanes  by,  300;  value  of  property  saved 
through  warnings  of,  301;  utility  of  warnings  of,  301,  302;  and 
warnings  to  mariners  on  Great  Lakes,  302 ;  inception  of  storms  de- 
tected by,  302 ;  expectations  of  future  forecasting  by,  303,  304 ; 
first  tentative,  established,  305 

Uranium,  nucleus  of  atom  of,  32 

Uranus,  atmosphere  of,  3 ;  and  heat  from  sun,  3 


INDEX  325 

VALLEYS,  influence  of,  on  temperature,  203,  204 

Vaporization,  latent  heat  of,  58,  59 

Vegetation,  oxygen  and,  36 ;  carbon  dioxide  and,  36 ;  and  frost,  85-97 

Velocity  increased  by  altitude,  wind's,  109-111 

Ventilation,  detrimental  effects  of  poor,  34;  need  of,  in  closed  or  low 
places,  36;  in  places  of  habitation,  37;  and  underground  apart- 
ments, 182,  183 

Vera  Cruz,  Mexico,  climate  of,  209 

Verkhoyansk,  Siberia,  extremes  of  temperature  at,  196,  197 ;  Christmas 
Day  in,  273 

Vienna,  Austria,  Christmas  Day  in/271 

V-Shaped  Lows.    See  Lows 

WARM  WAVES,  cause  and  duration  of,  136,  137 

Washington  Monument,  pressure  of  air  at  top  of,  79 

Water,  density  of,  compared  to  air,  15 ;  infinitesimal  size  of  molecule  of, 
30 ;  union  of  hydrogen  and  oxygen  to  constitute,  32 ;  and  bacteria, 
43 ;  commercial  and  scientific  unit  of  heat  and,  50,  51 ;  boiling  point 
of,  58 ;  boiling  point  of,  as  gauge  for  altitude,  60,  61 ;  frost  as  af- 
fected by  body  of,  90,  91;  rejects  heat  by  reflection,  172;  solar 
rays  penetrate,  173;  temperatures  of  large  bodies  of,  173;  differ- 
ence in  freezing  temperature  of  fresh  and  salt,  173 ;  salt,  better  con- 
ductor of  heat,  173;  a  wonderful  phenomenon  of  fresh,  173-175; 
low  temperature  of,  of  ocean  bottoms,  175,  176;  temperature  of, 
of  inclosed  seas  and  oceans,  176,  177 ;  latitude,  season  and  depth 
change  temperature  of,  177,  178;  direction  of  wind  affects  shore 
temperature  of,  178 ;  has  great  capacity  for  heat,  200,  201 

Water  vapor,  and  earth's  atmosphere,  8;  absorption  of  sun's  rays  by, 
8 ;  level  of,  8 ;  one  of  earth's  atmospheres,  29 ;  density  of,  37 ;  varies 
according  to  locality,  37,  38;  temperature  and,  38;  precipitation 
of,  38,  231 ;  transformations  of,  38 ;  and  the  dew  point,  38 ;  satura- 
tion point  and  temperature,  38 ;  measured  by  hygrometer,  39 ;  and 
frost,  85-97;  protects  earth  from  freezing,  170;  changes  in  sun's 
rays  effected  by,  170 ;  a  separate  atmosphere,  231 ;  and  raindrops, 
284 ;  rainfall  and  instantaneous  precipitation  of  all,  285 ;  and  snow, 
285-287;  and  fog,  288 

Waves,  difference  between  light,  heat  and  sound,  51 ;  length  of  different, 
of  solar  energy,  51 ;  velocity  of,  51,  52 

Weather,  forecasting,  with  aneroid  barometer,  74-79;  moon  has  no  in- 
fluence on,  138-140;  general  rules  for  forecasting,  149-153;  dif- 
ference between  climate  and,  161;  changes  daily,  161;  expecta- 
tions of  future  forecasting  of,  303,  304.  See  also  UNITED  STATES 
WEATHER  BUREAU 

"Weather  Forecasting  in  the  United  States  ".  151 

Weather  map,  value  of  aviator  in  compiling,  23;  112-160;  supplied  by 
Weather  Bureau,  112;  value  of,  112,  113;  advantage  of  familiarity 


326  INDEX 

Weather  map,  continued 

with,  113,  114;  method  of  compiling,  114;  collection  of  data  for, 
114, 115 ;  marking  isobars  on,  115 ;  Highs  and  Lows  of,  115, 116 ;  in- 
dication of  storm  action  on,  115;  arrows  fly  with  wind  on,  116, 
117;  winter  storm  of  1893  on,  117-123;  temperature  readings  on, 
119;  indication  of  storm  center  on,  121 ;  meaning  of  red  lines  on, 
122,  123 ;  forecasting  tornadoes  by  use  of,  144,  145 ;  general  rules 
for  forecasting  and  the,  149-153;  Prof.  Henry  compiles  first,  296. 
See  also  UNITED  STATES  WEATHER  BUREAU 

Weather  observers,  voluntary,  66-79 

Weather  observations,  from  kites,  64 ;  method  of  taking,  66-79 ;  extent 
of  area  under,  155 ;  practice  of  early  meteorologists  in,  155,  156 ; 
advantages  enjoyed  by  the  Weather  Bureau  in,  156-158.  See  also 
UNITED  STATES  WEATHER  BUREAU 

Weather  records,  serve  ends  of  justice,  79-83.  See  also  UNITED  STATES 
WEATHER  BUREAU 

Weight,  difference  between,  and  pressure  of  air,  77 

Wendham,  first  to  use  multiple  plane  kites,  64 

West  Indian  Hurricane.     See  HURRICANE 

Wheeling,  W.  Va.,  temperature  of  earth  at  depth  of  3490  feet  at,  179 

Wilson,  President  Woodrow,  removes  Prof.  Moore  from  office  of  chief  of 
Weather  Bureau,  306 

Wind,  and  pressure  of  the  globe,  98-111;  why  it  blows,  116;  cause  of 
variation  in  velocity  of,  116-117 

Winds,  trade,  101,  102 ;  of  middle  latitudes,  102,  103 ;  rain,  of  tropics, 
104,  105 ;  rain  in  the  region  of  west,  105 ;  variations  in  coastal, 
106 ;  monsoon,  106,  107 ;  Fohn,  107 ;  Chinook,  107 ;  deflected  by 
earth's  rotation,  107-109;  velocity  of,  as  affected  by  altitude, 
109-111 ;  West  Indian  hurricane,  133,  134 ;  of  Galveston  hurricane, 
134 ;  of  tornadoes,  141-148 ;  of  latitudes  30°  north  and  south,  194 

Winter  resorts,  with  favorable  climate,  251 

Winter  storm  of  1893,  117-123 

Winter  temperature  gradients  in  isothermal  stratum,  12 

XENON,  33 

YAKUTSK,  SIBERIA,  annual  range  of  temperature  at,  169 

ZERO,  absolute,  62 


14  DAY  USE 

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on  the  date  to  which  renewed. 
Renewed  books  are  subject  to  immediate  recall. 


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UNIVERSITY  OF  CALIFORNIA  UBRARY 


